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    NBER WORKING PAPER SERIES

    CHANGES IN U.S. HOSPITALIZATION AND MORTALITY RATES FOLLOWING

    SMOKING BANS

    Kanaka D. Shetty

    Thomas DeLeire

    Chapin White

    Jayanta Bhattacharya

    Working Paper 14790

    http://www.nber.org/papers/w14790

    NATIONAL BUREAU OF ECONOMIC RESEARCH

    1050 Massachusetts Avenue

    Cambridge, MA 02138

    March 2009

    We thank seminar participants at the Research in Progress Seminar at Stanford Medical School for

    their insights. We thank Dr. Alan Garber, Dr. Douglas Owens, and Dr. Mayer Brezis for their helpful

    comments. Finally, we thank Dr. Catherine Su and Dr. Priya Pillutla for helpful comments on earlier

    versions of this manuscript. The views in this paper are those of the authors and should not be interpreted

    as those of the Congressional Budget Office. Dr. Shetty was supported by a U.S. Veterans Affairs'

    Fellowship in Ambulatory Care Practice and Research. Dr. Bhattacharya thanks the U.S. National

    Institute on Aging for partial funding. The authors have no relationships (financial or otherwise) with

    any company making products relevant to this study. The views expressed herein are those of the author(s)

    and do not necessarily reflect the views of the National Bureau of Economic Research.

    2009 by Kanaka D. Shetty, Thomas DeLeire, Chapin White, and Jayanta Bhattacharya. All rights

    reserved. Short sections of text, not to exceed two paragraphs, may be quoted without explicit permission

    provided that full credit, including notice, is given to the source.

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    Changes in U.S. Hospitalization and Mortality Rates Following Smoking Bans

    Kanaka D. Shetty, Thomas DeLeire, Chapin White, and Jayanta Bhattacharya

    NBER Working Paper No. 14790

    March 2009

    JEL No. I1,I18

    ABSTRACT

    U.S. state and local governments are increasingly restricting smoking in public places. This paper

    analyzes nationally representative databases, including the Nationwide Inpatient Sample, to compare

    short-term changes in mortality and hospitalization rates in smoking-restricted regions with control

    regions. In contrast with smaller regional studies, we find that workplace bans are not associated with

    statistically significant short-term declines in mortality or hospital admissions for myocardial infarction

    or other diseases. An analysis simulating smaller studies using subsamples reveals that large short-term

    increases in myocardial infarction incidence following a workplace ban are as common as the large

    decreases reported in the published literature.

    Kanaka D. Shetty

    RAND Corporation

    1776 Main Street

    Santa Monica, CA 90401

    [email protected]

    Thomas DeLeire

    La Follette School of Public Affairs

    University of Wisconsin - Madison1225 Observatory Drive

    Madison, WI 53706

    [email protected]

    Chapin White

    Congressional Budget Office

    2nd and D Streets

    Washington, DC 20015

    [email protected]

    Jayanta Bhattacharya

    117 Encina Commons

    Center for Primary Careand Outcomes Research

    Stanford University

    Stanford, CA 94305-6019

    and NBER

    [email protected]

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    1Introduction

    Stateandlocalgovernmentshaveincreasinglybannedsmokinginpublicplaces

    (includingworkplaces,restaurantsandbars)asameansoflimitingnonsmoker

    exposureandofdiscouragingsmoking(CentersforDiseaseControlandPrevention

    2007).Severalrecentstudiesinthemedicalliteratureusingasmallnumberofregions

    suggestthatsmokingbansleadtoashortterm8to40%decreaseintheannual

    incidenceofacutemyocardialinfarction(AMI)(Sargent,Shepardetal.2004;Bartecchi,

    Alseveretal.2006;Cesaroni,Forastiereetal.2008).Despitethesefindings,itisunclear

    howwelltheresultswouldtranslatetotypicalU.S.communities.Weexaminewhether

    governmentalsmokingrestrictionsaffecthospitalizationandmortalityratesinalarge

    sampleofU.S.communities.

    WecalculatedeathandhospitalizationratesforAMIandotherdiseasesusing

    MedicareProviderAnalysisandReview(MEDPAR)files,nationaldeathrecords

    (otherwiseknownasthemultiplecauseofdeathfiles,hereafterMCD),and

    hospitalizationdatafromtheHealthcareCostandUtilizationProjectsNationwide

    InpatientSample(NIS).Wecompareratesbeforeandafterimplementationofthese

    bansrelativetocommunitiesthatdidnotimplementbans.Weusethevariationin

    implementationdatesacrossthecountryandfixedeffectsmodelstocontrolfor

    unobservablefactorsincludingimprovingpreventionandtreatmentofcardiovascular

    disease,decreasingsmokingrates,andsmokingrestrictionsenactedbyprivate

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    businesses.Wefindthatsmokingrestrictionsareunlikelytosubstantiallyaffectshort

    termmortalityandhospitalizationratesinboththeelderly,workingage,andchild

    populations.Wefindsomeevidencethatsmokingbanscouldreducemortalityinthe

    elderlybuttheresultsarenotstatisticallysignificant(1.4%,95%confidenceinterval:

    3.0to0.2%).

    Allpreviouspublishedstudiesonthehealtheffectsofsmokingbanssharea

    commonmethodology:theycomparetheoutcomesinasinglecommunitythathas

    passedasmokingbanwithoutcomesinasmallsetofnearbycommunitiesthathave

    notpassedbans. Amajorcontributionofthispaperisthatwesimulatetheresultsfrom

    allpossiblesmallscalestudiesusingsubsamplesfromthenationaldata. Wefindthat

    largeshorttermincreasesinAMIincidencefollowingasmokingbanareascommonas

    thelargedecreasesreportedinthepublishedliterature.

    2Background

    Inthissection,wediscusshowenvironmentaltobaccosmoke(alsoknownas

    secondhandsmoke)isrelatedtohealthoutcomes,thehistoryandeffectsofsmoking

    bansintheU.S.andinternationally,andtheimplicationofpreviousstudiesforU.S.

    smokingpolicy.

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    2.1Environmentaltobaccosmokeandhealthoutcomes

    Inarecentreview,theU.S.SurgeonGeneralreportsthatnumerous

    epidemiologicandlaboratorystudieshavelinkedenvironmentaltobaccosmoke(ETS)

    exposuretoincreasedratesofcardiovasculardisease,respiratoryillnessandlung

    cancer(GlantzandParmley1991;He,Vupputurietal.1999;BarnoyaandGlantz2005;

    U.S.DepartmentofHealthandHumanServices.2006).Laboratorystudiessupportthe

    notionthatsmallquantitiesofinhaledcigarettesmokecaninducesimilarbiochemical

    responsesinnonsmokersasinchronicsmokers.Sucheffectscouldpredisposenon

    smokerstogreatlyelevatedriskofAMIandstroke.Epidemiologicstudiestypically

    comparedoutcomesnonsmokingspousesofsmokersandnonsmokers.Although

    somemetaanalysesdisputedthesefindings,mostagreedthatchronicETSexposure

    increasedriskofAMIby20to30%.Althoughnoamountofsecondhandsmokeislikely

    tobebeneficial,theabovestudiesdonotaddressthepotentialeffectsofintermittent

    exposuretosecondhandsmoke,asmightbecausedbyexposuretocigarettesmokein

    publicplaces.

    SecondhandsmokeinpublicplaceshasbeenmoststronglylinkedtoAMI

    amongallpotentialadversehealthoutcomes(OngandGlantz2004;Sargent,Shepardet

    al.2004;Bartecchi,Alseveretal.2006).Thereissomebiologicaljustificationforthisin

    themedicalliterature(U.S.DepartmentofHealthandHumanServices.2006).Thefull

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    effectsofeliminatingtobaccosmokemaytakeyearstooccurbecausesomeaspectsof

    coronaryarterydisease(suchasnarrowingofthecoronaryarteries)developslowly

    overtime.However,aheartattackoccursduetosuddenclotformationindiseased

    arteries;inlaboratorysettings,exposuretoevensmallquantitiesoftobaccosmokecan

    inducebiochemicalstatesthatpredisposetoheartattacks.Therefore,asmokingban

    couldplausiblyreduceAMIincidenceandmortalityasearlyasthefirstyearafteraban

    ifiteliminatesevenrelativelyminorexposure.Asaresultmanypriorstudiesexamined

    AMIratesinsingleregionsinthe6to18monthsfollowingasmokingban.Inaddition

    toincreasedriskofAMI,thoseexposedtosecondhandtobaccosmokemaysuffer

    higherratesofasthma,chronicobstructivepulmonarydisease,infections,cancerand

    otherdiseases.

    2.2PublicbansonsmokinginU.S.publicplaces

    AsevidenceonETSaccumulated,manyU.S.employersbeganrestricting

    smokingintheworkplace;theproportionofcoveredworkersincreasedfrom25%to

    70%between1986and1993(Farkas,Gilpinetal.1999;Farrelly,Evansetal.1999;

    CentersforDiseaseControlandPrevention2000).Followingtheseprivaterestrictions,

    severalcommunitiesinCaliforniabannedsmokinginworkplaces,restaurants,andbars

    intheearly1990s.Manyotherstatesandmunicipalitiesfollowed(American

    Nonsmokers RightsFoundation2007).Inadditiontotheselocalpolicies,several

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    prominentpoliticiansadvocatedanationalpolicybanningsmokinginpublicplaces

    (OnTheIssues.org2007).

    Althoughthesebanshaveprovenpopular,thescientificliteraturetodatehas

    onlyexaminedtheimpositionofasmokingbaninafewspecificU.S.regionsand

    severalEuropeancountries.AMIratesdecreasedapproximately40%inHelena,

    Montanaand27%inPueblo,Colorado(relativetosurroundingcommunities)following

    theimpositionofbroadrestrictions(Sargent,Shepardetal.2004;Bartecchi,Alseveret

    al.2006).AlargerstudycomparedratesofAMIandacutestrokeadmissionsinNew

    YorkStatebeforeandaftercomprehensivesmokingbans,whichwerelargely

    implementedinMarchandJuly2003(Juster,Loomisetal.2007).Thisstudyestimated

    thatthelawsreducedAMIadmissionsby8%,althoughitdidnotcomparethese

    changesinAMIandacutestrokeadmissionstochangesthatmayhaveoccurredin

    nearbystatesthatdidnotimplementsmokingbansoverthisperiod.

    Examiningadifferentmechanism,AdamsandCotti(2008)findincreasedratesof

    vehiculardeathsfollowingtheenactmentofsmokingbans. Theyattributethisincrease

    tosmokersdrivingoutoftheirnativeareatofindaplacetosmokeinpublic. Another

    possibilityisthatthesebansleadsmokerstosmokemoreinvehicles,whichcouldbea

    distractionwhiledriving.AdamsandCottiusenationaldataandhencemeasuresthe

    averageeffectofabanacrossallcommunitiesintheU.S.;unlikethepreviouslycited

    studies,theydonotmeasuretheeffectinindividualcommunities.

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    2.3Internationalsmokingbans

    TworelativelylargestudiesoftheeffectofsmokingbansonAMIincidencein

    RomeandthePiedmontregionofItalyconcludedthatsmokingbansreducedAMI

    incidenceby7to11%inyoungerpopulations(BaroneAdesi,Vizzinietal.2006;

    Cesaroni,Forastiereetal.2008).Theauthorsdemonstratedthattheprevalenceof

    smoking,cigaretteconsumptionpersmoker,andnonsmokerexposuredroppedin

    Italyafterthenationalban(BaroneAdesi,Vizzinietal.2006;Gallus,Zuccaroetal.2007;

    Cesaroni,Forastiereetal.2008).1

    AstudyoftheScottishpublicsmokingbanfoundlargereductionsinAMIrates

    aswell(Pell,Hawetal.2008).TheScottishgovernmentimplementedacomprehensive

    baninMarch2006.Theauthorsmeasuredadmissionsto9hospitals(whichtreatover3

    millionpeople)aswellasdeathrecordsforthegeneralpopulation.Theymeasured

    actualexposuretocigarettesmokeamongnonsmokers(formersmokersandnever

    smokers)andcurrentsmokers.Inpriorstudiesofthegeneralpopulation,serum

    cotininelevelsdeclinedfrom0.43to0.25nanograms/dLinnonsmokersandfrom167

    to103nanograms/dLincurrentsmokers.Theauthorsthennotedstatisticallysignificant

    declinesinadmissionsforacutecoronarysyndromesinallgroups 14%insmokers,

    19%informersmokersand21%inthosewhoneversmoked.ThedeclineintheAMI

    1 The authors used cotinine levels, obtained from blood or salivary samples, to measure cigarette smoke exposure in

    non-smokers reliably.

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    ratewasnoticeablylargerthanthe4%declineinneighboringEnglandduringthesame

    timeperiod(whichlackedacomprehensiveban).

    2.5ImplicationsofpriorworkforU.S.smokingpolicy

    Theaforementionedstudieslinkingsmokingbanstoimpressivepublichealth

    gainssuggestthatwidespreadpublicsmokingbanswoulddemonstrablyimproveU.S.

    publichealth.However,theinternationalexperiencealsomaynottranslatebecause

    nonsmokersexposuretosecondhandsmokeandsmokingprevalenceinItalyandin

    Scotlandweremuchhigherandprivatesmokingrestrictionswereweakerthaninthe

    U.S.

    RestrictingtheanalysistoU.S.studiesdoesnoteliminatequestionsabout

    generalizability.PriorU.S.studiesweresmallinscale,havingexaminedonlyafew

    regions;itispossiblethatthoseregionsarenotrepresentativeoftypicalU.S.

    communities.Althoughdifferenceindifferenceanalysescancontrolforunobserved

    factors,asimplepairwisecomparisonusinganatypicalpairofcommunitieswillyield

    resultsthatmaynotberepresentative.Bycontrast,asimulationstudyfoundthat

    extendingsmokingrestrictionsfrom70%to100%ofU.S.workplaceswouldprevent

    roughly1,500myocardialinfarctionsinthefirstyear(OngandGlantz2004).Although

    thismaybeaclinicallyrelevantimprovement,itrepresentsamuchsmallerreduction

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    (

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    similarityimpliesexposuretosecondhandsmokepresentslargeheathrisksatlow

    levelsandnoadditionalhealthrisksathigherlevels,whichseemsunlikely.2

    WeaddresstheseissuesbyanalyzingtheimpactofU.S.publicsmoking

    restrictionsonhealthoutcomesinalarge,heterogeneousgroupofU.S.communities.By

    analyzingmuchlargerpopulationsinadiversegroupofU.S.hospitalsandcounties

    andbyaccountingforunderlyingseculartrendsandregionspecificcharacteristics,we

    mitigatethepossibilityofselectionbias.

    3.Data

    Toconstructthedatasetsusedforouranalysis,wemergedataonthetimingand

    locationofsmokingbanstothreelargenationwidedatasourcesonhealthoutcomes.

    3.1Dataonsmokingbans

    WeuseordinancedatafromtheAmericanNonsmokersRightsFoundationto

    identifystates,counties,andmunicipalitiesthatimplementedrestrictionsonsmoking

    between1990and2004.WeadapttheclassificationschemefromtheAmerican

    NonsmokersRightsFoundationtoidentifythosebansthatrestrictsmokinginall

    workplacesexceptbarsandrestaurantsasworkplacebans.Althoughnotincludedin

    2Similar risk reductions were found in European and U.S. studies though baseline smokingprevalence, secondhand smoke exposure, and efficacy varied, which argues against a plateauin risk.

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    theformerlist,Californiaadoptedanearlycompletebanonworkplacesmokingin

    1995.WeclassifiedCaliforniaassmokingrestrictedstartingin1995.Wealsocreatea

    datasetofbansofanysite workplaces,barsorrestaurants.Weclassifyeach3digitzip

    code,city,andcountyintheU.S.bysmokingbanstatusanddateofimplementation.

    3.2Datasourcesforhealthoutcomes

    WeanalyzehealthoutcomesusingtheMultipleCauseofDeath(MCD)database

    (19892004),Medicareclaims(19972004),andtheNationwideInpatientSurvey(NIS),

    collected19932004bytheHealthcareCostandUtilizationProject,whichissponsored

    bytheAgencyforHealthcareResearchandQuality(AgencyforHealthcareResearch

    andQuality2006).TheMCDdatabaseidentifiestheunderlyingcauseforeachdeathin

    theU.S.OursourceforMedicareclaimsaretheMedicareProviderAnalysisand

    Review(MEDPAR)files,whichincludeallfeeforserviceMedicarebeneficiariesinthe

    U.S.TheNISisanationallyrepresentative20%sampleofalldischargesfromU.S.

    communityhospitals(whichincludesallnonfederalacutecarehospitals).Excluded

    hospitalsincludeVeteransAffairshospitalsandlongtermrehabilitationhospitals.

    Weidentifiedmortalityandhospitalizations duetoAMIandallcausedeaths

    andhospitalizationsbecausebothmightplausiblyimproveintheshortrun.In

    addition,broaddiseasemeasureslikeAMIandallcauseeventsarelesslikelymiscoded

    inadministrativedata,reducingmeasurementerror(Petersen,Wrightetal.1999;

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    TirschwellandLongstreth2002).Wealsoconsidercasesofasthmaandchronic

    obstructivepulmonarydisease;whilethesearechronicdiseases,secondhandsmoke

    possiblytriggersacuteexacerbations(U.S.DepartmentofHealthandHumanServices.

    2006).Wealsoidentifyhipfracturehospitalizationsbecausethesecanactasanegative

    controlbecausetheirincidencewouldbeunlikelytochangequicklyafterasmoking

    ban(Hoidrup,Prescottetal.2000). Wedontexpecttheincidenceofhipfracturetobe

    affectedbysmokingbans. Ifweweretofindanassociationbetweensmokingbansand

    theincidenceofhipfracture,wewouldquestionthevalidityoftheempiricalstrategy.

    Weassembleeachdatasetinasimilarfashion:wefirstclassifydeathsand

    hospitaladmissionsaccordingtotheirprimarydiagnoses(AMI,asthma,etc.);wethen

    sumalloutcomesineachregion(hospitalcatchmentarea,county,orzipcode);finally,

    wemergeinformationonsmokingordinancesforthatregion.

    Workplacesmokingbanscouldhavedifferentialeffectsbyage.Theelderlyand

    childrenmaybemorevulnerabletothediseasesexacerbatedbyETS,andcouldstandto

    gainmorebenefitthanatypicalworkingadult.Ontheotherhand,childrenandthe

    elderlyareprimarilyexposedtoworkplaceETSascustomers,whichwouldreduce

    theirbenefitfromasmokingban.Toaccountforthesedifferences,wefurtherstratify

    outcomesintothreeagegroupsperregion:children(017years),workingageadults

    (1864years),andtheelderly(65+years).

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    Fromeachdataset,weexcludedeathsandhospitalizations whereweareunable

    todeterminewhetherthepersonlivedinanareawhereasmokingrestrictionwas

    implemented(3540%oftheNISandMCDdata).Inaddition,weexcludethefollowing

    fromouranalysisofNIShospitals:transferpatients,hospitalsincludedinasingle

    surveyyear,hospitalsthatmergedduring19932004,hospitalsdevotedtoacute

    rehabilitation(becausefewAMIsareadmitted)andsmallhospitals(

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    example,manyregionsexperiencedunobservedincreasesinprivatesmoking

    restrictions,reductionsinsmokingprevalence,orimprovedmedicaltreatmentthat

    couldhavecausedchangesinoutcomes.Tomitigatethesepotentialconfounding

    factors,wecomparetrendsinregionswheresmokingbanswereimplementedtothose

    incontrolregionswheresmokingrestrictionswerenotimposed.Inparticular,we

    estimateregionfixedeffectsmodels. Foreachoutcome(e.g,AMIdeathor

    hospitalizations), weusethefollowingregressionmodel:

    (1) ititstiit SmokingBanOutcome +++=

    Here itOutcome representsthenumberofdeathsorhospitaladmissionsinregion

    i(1N)andtimet(1T), itOutcome isanindicatorforeachyear,and it istheerror

    term.Weinclude i ,anindicatorforeachregion(county,3digitzipcode,orhospital),

    tocontrolforidiosyncraticdifferencesbetweenregions. s isthecoefficientofinterest,

    representingthebreakinthetimetrendinducedbyasmokingban,aftercontrollingfor

    seculartrends.Inpresentingfinalresults,wepresentthemeanpercentagechangein

    outcomes %)100(

    swhere is = =

    N

    i

    T

    t itOutcome

    TN 1 11

    .Weuseblockbootstrap

    clusteredattheregionalleveltocalculateallstandarderrors.Ofnote,theeffectsof

    privaterestrictionsenactedpriortoagovernmentbanareincludedinprebantrends

    andareexcludedfromthefinalestimate.Asaresult,thisstrategyplausiblyidentifies

    theshorttermeffectsofgovernmentrestrictionsalone.Duetodatalimitations,wealter

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    ourapproachinanalyzinghospitaladmissionsinNIShospitals;wecomparechangesin

    admissionsinthefirstyearfollowingasmokingrestrictiontochangesincontrol

    hospitalswithoutsmokingrestrictions.3

    4.2Sensitivityanalyses.

    Inourmainregressionmodel(1)wedonotincludecovariatesotherthantime

    andregionspecificindicators.However,itispossiblethatfactorsmightchangeover

    timedifferentiallybetweenregions.Ifso,thefixedeffectsmodelwouldyieldbiased

    estimates.Wethereforetestmodelspecificationsofthefollowingform:

    (2) ititstiit SmokingBanOutcome ++++= X

    Thetermsandresultsarethesameasin(1)exceptfortheadditionofX,avectorof

    countylevelcharacteristicstakenfromthe2005AreaResourceFile.Thevariables

    includepopulationsize,numberofphysiciansandhospitalbedspercounty,household

    income,andpercentofpopulationinlaborforce.Thesedatawerelinkedbycountyand

    year,whereavailable,tocountiesfromtheMCDaswellashospitalsintheNISdata.

    Wedonotincludethesevariables(whichcouldpotentiallyaddexplanatorypower)in

    3In our analysis of the NIS data, our primary unit of analysis is the hospitalscatchment area, which includes the hospitals home city but whose full extent is unobservable.We use the number of admissions to a hospital in a particular month as a measure of theadmission rate within its catchment area. Catchment areas tend to remain stable over time, sothe approximation error is likely to be small. It is possible that we misclassified someadmissions. However, many bans were enforced in the county or state of origin, which wouldinclude the entire catchment area. In addition, we only considered patients with seriousillnesses who tend to be taken to the nearest hospital, which further reduces bias.

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    allmodelspecificationsbecausedataforX isoftenmissingforseveralyears,which

    substantiallylimitstheirsamplesizes.Weperformsensitivityanalysesbycomparing

    theresults

    using

    model

    specification

    (2)

    to

    the

    results

    using

    model

    specification

    (1)

    for

    thesamesetofincludedregions.

    4.3Simulatingsmallsampleresults

    Wecompleteouranalysisbyusingsubsamplesofthenationaldatatosimulatea

    completesetofpairwisecomparisonstudiesofthesortavailableinthepublished

    literature,includingBartecchietal.(2005)andSargentetal.(2004).Thesestudies

    comparedatreatmentunitwhereabanwaspassedagainstacontrolunitwithnoban

    onthebasisofthechangeinanoutcomevariable(heartattackadmissionrates,for

    instance)inashortperiod(618months)afterthebanwaspassedinthetreatment

    region.Wesimulatetherangeofsucheffectsbyfirstcalculatingthepercentchangein

    admissionsineachhospitallocatedinaregionwithworkplacesmokingrestrictions

    betweentheyearbeforeandtheyearfollowingaworkplacesmokingban;wealso

    calculatethesamestatisticsforallcontrolhospitalsfromthesametimeperiod.Wethen

    subtractthechangeinoutcomesineachcontemporaneouscontrolhospitalfromeach

    interventionhospital.Theresultingdatasetconsistsoftheuniverseofpossible(19,406)

    pairwisecomparisonsofonesmokingrestrictedhospitalwithonecontrolhospital.We

    conductasimilaranalysisofheartattackmortality,exceptinthiscase,weuseMCD

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    mortalitydataandourunitofanalysisisthecounty.Thefinaldatasetconsistsof23,938

    pairwisecomparisonsandrepresentstheuniverseofsuchcomparisonsintheMCD

    data.

    5.Results

    5.1Smokingrestrictionsovertime

    ThepercentageofU.S.regionsthatimposedsmokingrestrictionsincreased

    dramaticallybetween1988and2004;theprevalenceofsmokingrestrictionsrose

    sharplyin1995and20032004andmoregraduallyinotheryears(seeFigure1).

    Notably,thisnationaltrendfollowstheactionsofprivateemployers.By1993,most

    workplacesisolatedcigarettesmoke,whichwoulddiminishtheimpactoflegislative

    bans(Farrelly,

    Evans

    et

    al.

    1999;

    Centers

    for

    Disease

    Control

    and

    Prevention

    2000).

    5.2Mainestimates

    Workplacesmokingrestrictionsareunrelatedtochangesinallcausemortalityor

    mortalityduetootherAMIinallagegroups.Restrictionsonsmokingofanysortare

    associatedwithreducedallcausemortalityamongtheelderly(1.4%,95%CI: 3.0to

    0.2%)buttheresultisonlysignificantatthe10%level(p=0.06)(seeTable2).

    WefindnostatisticallysignificantreductioninadmissionsduetoAMIamong

    workingageadults(4.2%,95%CI: 10.2to1.7%,p=0.165)oramongtheelderly(2.0%,

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    95%CI: 3.7to7.7%,p=0.48)followingtheenactmentofaworkplacesmoking

    restriction(seeTable3).Wesimilarlyfindnoevidenceofreductioninadmissionsfor

    otherdiseasesinanyagegroup,thoughsmokingrestrictionsofallsortsareassociated

    withstatisticallyinsignificantincreasesinasthma(11.4%, 95%CI: 2.4to25.3%,p=0.11)

    andtotaladmissions(3.7,95%CI: 2.1to9.5%,p=0.21)amongchildren.Amongboth

    theelderlyandworkingageadults,wefindnostatisticallysignificanteffectofsmoking

    bansonhipfractureadmissions,ournegativecontrol.Thissupportsthehypothesisthat

    unobservedcharacteristicsofregionsdonotconfoundourresults.

    5.3Sensitivityanalyses

    Solelyusingregionspecificindicatorstocapturetrendspotentiallyomits

    importantconfoundingvariablesbutcomprehensivedataisnotavailableforallregions

    andyears.Wetestforbiasbyaddingvariablesfordemographicsandmedicalresource

    availabilitytotheregressionmodel.(Weobtainthesedatafromthe2005AreaResource

    File,whichcontainsinformationforallcountiesandsomeyears.)Weexaminethe

    importanceoftheseomittedvariablesbycomparingresultswithandwithout

    additionalvariablesforthesametimeperiods.

    Table4showstheeffectofanysmokingbanontotaldeathratesinallagegroups

    usingdifferentsetsofcontrolvariables.Theestimatesdonotchangedramaticallywith

    inclusionofdifferentvariables,butdochangeasthestudysamplechanges. Thesample

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    isreducedfrom24,884countyquartersincolumn(1)to7,308countyquartersin

    column(4).Regressionestimatesusingthesamesamplesbutdifferentregression

    modelsaresimilar. Forexample,basedonalimitedsampleof15,512countyquarters

    across9yearsincolumn(3),theestimatedassociationbetweenanysmokingbanand

    totaldeathrateswas+0.330%(withastandarderrorof0.794%)withoutadditional

    controlsand+0.328%(withastandarderrorof0.804%)withcontrolsforhospitalbeds

    percapitaandphysicianspercapita.WeshowsimilarresultsinTables5and6.These

    resultssuggestthatordinarydemographicchangesareaccountedforusingthe

    differenceindifferenceidentificationstrategy.

    Inalloftheresultsreportedinthetables,wecalculatestandarderrorsthatallow

    forclusteringatthearealevel(county,hospitalarea,orzipcode). Ifinaddition,we

    weretocorrectformultiplecomparisonsusingHochbergsmethod(Hochberg1988),

    ourstandarderrorsincreasefurther.

    5.5Pairwisecomparisonssimulatingsmallsampleresults

    Figures2and3plotallpossiblepairwisecomparisonsofchangesinAMI

    incidenceafteraworkplacesmokingbantochangesinrandomlyselectedcontrol

    regions.Figure2showsthatthemeanmeasuredeffectofworkplacesmokingbanson

    heartattackadmissionsisclosetozero,but10%orgreaterdeclinesand10%ofgreater

    increasesinAMIadmissionsarecommon.Figure3showssimilarresultsfora

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    comparisonofAMImortalityinsmokingrestrictedcountiesfromtheyearaftera

    workplacebanwithratesincountieswithoutaban. Theresultsofthissimulation

    analysisshowsthatresultsfrompriorsmallsamplestudies,whichfoundverylarge

    decreasedinAMIadmissionsandmortalityfollowingtheenactmentofsmokingbans,

    arefeasible. However,resultswiththeoppositesignandofsimilarmagnitudearealso

    feasibleandshouldbeequallycommon.

    6.Conclusions

    WefindnoevidencethatlegislatedU.S.smokingbanswereassociatedwith

    shorttermreductionsinhospitaladmissionsforacutemyocardialinfarctionorother

    diseasesintheelderly,childrenorworkingageadults.Wefindsomeevidencethat

    smokingbansareassociatedwithareducedallcausemortalityrateamongtheelderly

    (1.4%)butonlyatthe10%significancelevel.

    Wealsoshowthatthereiswideyeartoyearvariationinmyocardialinfarction

    deathandadmissionrateseveninlargeregionssuchascountiesandhospital

    catchmentareas.Comparisonsofsmallsamples(whichrepresentsubsamplesofour

    dataandaresimilartothesamplesusedinthepreviouspublishedliterature)might

    haveledtoatypicalfindings.Itisalsopossiblethatcomparisonsshowingincreasesin

    cardiovasculareventsafterasmokingbanwerenotsubmittedforpublicationbecause

    theresultswereconsideredimplausible.Hence,thetruedistributionfromsingle

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    regionswouldincludebothincreasesanddecreasesineventsandameanclosetozero,

    whilethepublishedrecordwouldshowonlydecreasesinevents.Thus,publicationbias

    couldplausiblyexplainwhydramaticshorttermpublichealthimprovementswere

    seeninpriorstudiesofsmokingbans.

    Ourstudyfocusesonlyonthehealtheffectsofsmokingbans. Futureresearch

    shouldestimatenonhealthrelatedbenefitsofthesebanstononsmokers.Priortoa

    smokingban,nonsmokersatriskforrespiratorysymptomsorcardiovascularevents

    mighthaveavoidedbusinesseswithhighETSlevels.Afteraban,nonsmokerscould

    gaincomfortableaccesstothesebusinesses,butbasedonourfindingsinthisstudy,this

    benefitwouldnotalsoresultinreducedhospitalizationordeathrates.Ourstudy

    designplausiblyidentifiesonlyshorttermbenefitsofsmokingbans(ashasthestudy

    designsusedbypreviousstudies).Wecannotanalyzewhethersmokingbansimprove

    longtermtrendsforchroniccardiovasculardiseaseorlungcancer.Inaddition,

    smokingbansmayinducesmokerstoquitordiscouragenonsmokersfromstarting

    smoking.Thesepotentiallongtermbenefitswillnotbeapparentinstudyofshortterm

    outcomesandwouldbenefitfromfurtherstudy.

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    Agency for Healthcare Research and Quality. (2006). "INTRODUCTION TO THE HCUPNATIONWIDE INPATIENT SAMPLE (NIS), 2004." Retrieved 18 December 2007,

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    implementation of a comprehensive statewide smoking ban--New York, June 26, 2003-

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    Evans, W., M. Farrelly, et al. (1999). "Do Workplace Smoking bans Reduce Smoking?"American Economic Review 89(4): 728-747.

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    Gallus, S., P. Zuccaro, et al. (2007). "Smoking in Italy 2005-2006: effects of a comprehensive

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    He, J., S. Vupputuri, et al. (1999). "Passive smoking and the risk of coronary heart disease--a

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    Biometrika 75(4): 800-2.Hoidrup, S., E. Prescott, et al. (2000). "Tobacco smoking and risk of hip fracture in men and

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    Juster, H. R., B. R. Loomis, et al. (2007). "Declines in hospital admissions for acute myocardial

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    Longo, D. R., R. C. Brownson, et al. (1996). "Hospital smoking bans and employee smokingbehavior: Results of a national survey." Jama 275(16): 1252-7.

    Metzger, K. B., F. Mostashari, et al. (2005). "Use of pharmacy data to evaluate smoking

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    Ong, M. K. and S. A. Glantz (2004). "Cardiovascular health and economic effects of smoke-freeworkplaces." Am J Med 117(1): 32-8.OnTheIssues.org. (2007). "2007 Democratic primary debate at Dartmouth College." Retrieved

    18 December 2007, from

    http://www.ontheissues.org/Archive/2007_Dem_primary_Dartmouth_Drugs.htm .

    Pell, J. P., S. Haw, et al. (2008). "Smoke-free legislation and hospitalizations for acute coronarysyndrome." N Engl J Med 359(5): 482-91.

    Petersen, L. A., S. Wright, et al. (1999). "Positive predictive value of the diagnosis of acute

    myocardial infarction in an administrative database." J Gen Intern Med14(9): 555-8.Sargent, R. P., R. M. Shepard, et al. (2004). "Reduced incidence of admissions for myocardial

    infarction associated with public smoking ban: before and after study." Bmj 328(7446):

    977-80.Thun, M., J. Henley, et al. (1999). "Epidemiologic studies of fatal and nonfatal cardiovascular

    disease and ETS exposure from spousal smoking." Environ Health Perspect 107 Suppl 6:

    841-6.Tirschwell, D. L. and W. T. Longstreth, Jr. (2002). "Validating administrative data in stroke

    research." Stroke 33(10): 2465-70.

    U.S. Department of Health and Human Services. (2006). The Health Consequences of

    Involuntary Exposure to Tobacco Smoke: A Report of the Surgeon General. USDHS.Atlanta, GA.

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    Figure1

    0

    10

    20

    30

    40

    Percentageofregionswithbans

    1988 1992 1996 2000 2004Year

    Any smoking restriction

    Workplace restriction

    Regions are 3 digit US postal (zip) codesSource: Authors' analysis of data from American Non-smoker's Rights Foundation and California Department of Industrial Relations

    Figure 1. Prevalence of smoking bans over time

    Regionsare3digitU.S.postal(zip)codes

    Source:AuthorsanalysisofdatafromAmericanNonsmokersRightsFoundationand

    CaliforniaDepartment

    of

    Industrial

    Relations

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    Figure2.

    0

    2

    4

    6

    8

    10

    Percent

    -200 -150 -100 -50 0 50 100 150 200Relative difference in acute myocardial infarction incidence (%)

    Percent change

    Normal density curve

    Mean change

    Source: HCUP. Hospitals with smoking restrictions: 77. Control hospitals: 631 Pairwise comparisons: 19406

    Figure 2. Changes in AMI admissions relative to all control hospitals

    Source:AuthorsanalysisofdatafromNationwideInpatientSample.Hospitalswith

    smokingrestrictions:52.Controlhospitals:336.Pairwisecomparisons:8,529.Relative

    differencemaybelessthan 100%ifalargepercentageincreaseinacontrolhospitalis

    subtractedfromalargedecreaseinasmokingrestrictedhospital.

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    Figure3.

    0

    2

    4

    6

    8

    1

    0

    Percent

    -75 -50 -25 0 25 50 75Relative difference in acute myocardial infarction incidence (%)

    Percent change

    Normal density curve

    Mean change

    Source: MCD. Counties with smoking restrictions: 89. Control counties: 462 Pairwise comparisons: 23938

    Figure 3. Changes in AMI deaths relative to all control counties

    Source:AuthorsanalysisofdatafromMultiplecauseofdeathdatabase.Countieswith

    smokingrestrictions:89.Controlcounties:462.Pairwisecomparisons:23,905.Relative

    differencemaybelessthan 100%ifalargepercentageincreaseinacontrolcountyis

    subtractedfromalargedecreaseinasmokingrestrictedcounty.

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    Table1.Datasourcecharacteristics

    Datasource

    NationwideInpatientSample:

    Hospitals 874

    States

    27

    Years 19932004

    Alladmissions 21,820,484

    Admissionsbydisease

    Acutemyocardialinfarction 217023

    CombinedasthmaandCOPD 433674

    MultipleCauseofDeath:

    Counties 468

    States 50

    Years 19892004

    Alldeaths 24,610,532

    Acutemyocardialinfarction 2,042,812

    Medicarepatients:

    Regions(3digitzipcodes) 868

    States 51

    Years 19972004

    IncludedMedicarepopulation(personyears) 275,303,008

    Alldeaths 13,106,175

    Alladmissions

    Admissionsby

    disease

    72,542,544

    Acutemyocardialinfarction 2,382,386

    CombinedasthmaandCOPD 2,984,382

    Hipfracture 3,381,690

    Chronicobstructivepulmonarydisease

    Source:AuthorsanalysisofdatafromNationwideInpatientSample,MultipleCauseof

    Deathfiles,and100%MedicareProviderAnalysisandReviewfiles.

    Chronicobstructivepulmonarydisease

    Source:AuthorsanalysisofdatafromNationwideInpatientSample,nationaldeath

    statistics,and100%MedicareProviderAnalysisandReviewfiles.

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    Table2.Mortalityandsmokingrestrictions*

    Disease %changeinmortality(95%CI) Pvalue

    Workplacesmokingrestrictions:

    Alldeaths

    (0

    17

    years

    old)

    4(10.2

    to

    2.2)

    0.204

    AMI (1864yearsold) 4.4(11.6to2.7) 0.224

    Alldeaths(1864yearsold) 1.1(2.9to0.8) 0.247

    Alldeaths(age65+) 0.8(1.2to2.8) 0.413

    AMI(allages) 1.5(4.8to1.8) 0.374

    Alldeaths(allages) 0.3(1.6to0.9) 0.624

    Anysmokingrestrictions:

    Alldeaths(017yearsold) 2(6.5to2.6) 0.400

    AMI(1864yearsold) 3.5(10to3.1) 0.299

    Alldeaths(1864yearsold) 0.4(2.1to1.2) 0.601

    Alldeaths(age65+) 1.4(3.0to0.2) 0.062

    AMI(allages) 1.1(4.1to1.9) 0.470

    Alldeaths(allages) 0.5(0.6to1.6) 0.396

    *AuthorsanalysisofdatafromMultipleCauseofDeathfiles,years19932004exceptin

    age65+,whicharefrom100%MedicareProviderAnalysisandReviewfiles,19972004.

    AMIindicatesdeathsfromacutemyocardialinfarction.

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    Table3.Hospitaladmissionsandsmokingrestrictions

    Disease %changeinadmissions

    (95%CI)

    Pvalue

    Workplacesmokingrestrictions:

    Alladmissions

    (age

    017)

    3.7

    (2.1

    to

    9.5)

    0.211

    Asthma(age017) 11.4(2.4to25.3) 0.106

    AMI(age1864) 4.2(10.2to1.7) 0.165

    Alladmissions(age1864) 2.2(0.4to4.8) 0.101

    Asthma(age1864) 3.4(6.2to13.1) 0.485

    COPD(age1864) 1.7(8.6to12) 0.746

    Hipfracture(age1864) 5.1(15.6to5.4) 0.340

    AMI(age65+) 2(3.7to7.7) 0.477

    Alladmissions(age65+) 1.8(3.1to6.7) 0.477

    Asthma(age65+) 0.8(13.5to15.1) 0.909

    COPD(age65+) 3.4(3.6to10.5) 0.343

    Hipfracture(age65+) 0.1(2.4to2.6) 0.946

    Anysmokingrestrictions:

    Alladmissions(age017) 4.6(0.9to10.1) 0.101

    Asthma(age017) 13.7(2to29.3) 0.087

    AMI(age1864) 4.7(10.3to01) 0.104

    Alladmissions(age1864) 2.3(0.3to4.9) 0.083

    Asthma(age1864) 3.5(5to11.9) 0.422

    COPD(age1864) 2.1(11.8to7.7) 0.676

    Hipfracture

    (age

    18

    64)

    4.7

    (14.6

    to

    5.1)

    0.348

    AMI(age65+) 5.1(0.4to10.6) 0.068

    Alladmissions(age65+) 1.7(2.0to5.4) 0.364

    Asthma(age65+) 6.8(4.78to18.4) 0.246

    COPD(age65+) 2.7(2.4to7.8) 0.303

    Hipfracture(age65+) 1.1(1.4to3.6) 0.385

    Source:AuthorsanalysisofdatafromNationwideInpatientSample(199320004)except

    age65+,whicharefrom100%MedicareProviderAnalysisandReviewfiles,years1997

    2004.

    Acutemyocardialinfarction/Ischemicheartdisease

    Chronicobstructivepulmonarydisease

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    Table4.Comparisonofregressionmodels:

    Allcausemortalityfollowingsmokingbanofanysort(MCDcounties)Variablesincluded (1) (2) (3) (4)

    Anybans 0.495 0.324 0.328 1.335

    (0.583) (0.573) (0.794) (0.547)

    Hospitalbeds/person 0.0031

    (0.0013)

    Countypopulation 0.00005 0.00006 0.00005 0.00009

    (0.00002) (0.00002) (0.00002) (0.00003)

    Physicians/person 0.0003 0.0002 0.0007

    (0.0007) (0.0008) (0.0010)

    Percentpopulationinlaborforce 4.5

    (6.6)

    #Yearsinsample 15 13 9 5

    #observations 24884 21580 15512 7308

    Resultsfrom

    original

    model

    0.495 0.322 0.330 1.343

    (0.583) (0.573) (0.804) (0.546)

    *Eachcoefficientrepresentsthe%changeinoutcomesduetoa1unitchangeinthe

    explanatoryvariable. Standarderrorsareclusteredatthearealevelandarereported

    inparentheses.

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    Table5.Comparisonofregressionmodels:

    Myocardialinfarctionadmissionratesinworkingageadults(NIShospitals)

    followingworkplacebansVariablesincluded (1) (2) (3) (4)

    Workplacebans 4.2 4.1 13.3 9.2

    (3.1) (3.0) (5.8) (5.9)

    Hospitalbeds/person 0.0054

    (0.0029)

    Countypopulation 0.00004 0.00004 0.00003 0.00023

    (0.00003) (0.00003) (0.00002) (0.00008)

    Physicians/person 0.0024 0.0020 0.0027

    (0.0025) (0.0028) (0.0077)

    Percentpopulationinlaborforce 310.3

    (324.9)

    #Yearsinsample 12 12 9 5

    #observations

    7476 7476 4932 1502

    Resultsfromoriginalmodelon

    thissample

    4.2 4.2 13.3 9.2

    (3.1) (3.1) (5.8) (5.7)

    *Eachcoefficientrepresentsthe%changeinoutcomesduetoa1unitchangeinthe

    explanatoryvariable. Standarderrorsareclusteredatthearealevelandarereported

    inparentheses.

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    Table6.Comparisonofregressionmodels:

    Allcauseadmissionratesinworkingageadults(NIShospitals)

    Variablesincluded (1) (2) (3) (4)

    Workplacebans 2.20 2.12 0.35 1.52

    (1.34) (1.33) (1.73) (2.10)

    Hospitalbeds/person 0.000297

    (0.000998)

    Countypopulation 0.00004 0.00004 0.00003 0.00013

    (0.00002) (0.00002) (0.00002) (0.00004)

    Physicians/person 0.00126 0.00119 0.00185

    (0.000993) (0.00109) (0.00299)

    Percentpopulationinlaborforce 8.2

    61.8)

    #Yearsinsample 12 12 9 5

    #observations

    7476 7476 4932 1502

    Resultsfromoriginalmodel 2.20 2.20 0.26 1.40

    (1.34) (1.34) (1.73) (2.08)

    *Eachcoefficientrepresentsthe%changeinoutcomesduetoa1unitchangeinthe

    explanatoryvariable. Standarderrorsareclusteredatthearealevelandarereported

    inparentheses.


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