6 The RAND Corporation is a nonprofit om

advertisement
THE ARTS
This PDF document was made available
CHILD POLICY
from www.rand.org as a public service of
CIVIL JUSTICE
the RAND Corporation.
EDUCATION
ENERGY AND ENVIRONMENT
Jump down to document6
HEALTH AND HEALTH CARE
INTERNATIONAL AFFAIRS
NATIONAL SECURITY
POPULATION AND AGING
PUBLIC SAFETY
SCIENCE AND TECHNOLOGY
SUBSTANCE ABUSE
TERRORISM AND
HOMELAND SECURITY
TRANSPORTATION AND
INFRASTRUCTURE
WORKFORCE AND WORKPLACE
The RAND Corporation is a nonprofit
research organization providing
objective analysis and effective
solutions that address the challenges
facing the public and private sectors
around the world.
Support RAND
Browse Books & Publications
Make a charitable contribution
For More Information
Visit RAND at www.rand.org
Explore RAND Health
View document details
This product is part of the RAND Corporation reprint series.
RAND reprints present previously published journal articles,
book chapters, and reports with the permission of the publisher.
RAND reprints have been formally reviewed in accordance with
the publisher’s editorial policy, and are compliant with RAND’s
rigorous quality assurance standards for quality and objectivity.
*OURNALOF0HYSICAL!CTIVITYAND(EALTH33
Ú(UMAN+INETICS)NC
0HYSICAL!CTIVITYAND#HANGESIN(EALTH
#ARE#OSTSIN,ATE-IDDLE!GE
4ATIANA!NDREYEVAAND2OLAND3TURM
"ACKGROUND0HYSICALACTIVITYHASCLEARHEALTHBENElTSBUTTHEREREMAINSUNCER
TAINTYABOUTHOWITAFFECTSHEALTHCARECOSTS/BJECTIVE4OEXAMINEHOWPHYSICAL
ACTIVITYISASSOCIATEDWITHCHANGESINHEALTHEXPENDITUREFORANATIONALSAMPLEAGE
TOYANDESTIMATEHOWTHISASSOCIATIONVARIESACROSSPEOPLEWITHDIFFERENT
CHRONICDISEASESANDHEALTHBEHAVIORS-ETHODS$ATAWEREFROMTHE(EALTHAND
2ETIREMENT3TUDYANATIONALLONGITUDINALSURVEYOFLATEMIDDLEAGE!MERICANS
2ESULTS#ORRECTINGFORBASELINEDIFFERENCESINACTIVEANDINACTIVEGROUPSPHYSICAL
ACTIVITYWASASSOCIATEDWITHREDUCEDHEALTHCARECOSTSOFABOUTOVERYOR
ANNUALLY#ONCLUSIONS2EGULARPHYSICALACTIVITYINLATEMIDDLEAGEMAY
LOWERHEALTHEXPENDITUREOVERTIMEANDTHEEFFECTISLIKELYTOBEMOREPRONOUNCED
FORTHEOBESESMOKERSANDINDIVIDUALSWITHSOMEBASELINEHEALTHPROBLEMS7HILE
SUBSTANTIALLYLARGEFORTHEHEALTHCARESYSTEMOURESTIMATESAREMUCHSMALLERTHAN
HEALTHUNADJUSTEDCOMPARISONSORCROSSSECTIONALEFFECTS
+EY7ORDSHEALTHBEHAVIORMEDICALEXPENDITURES
4HEHEALTHBENElTSOFREGULARPHYSICALACTIVITYAREWELLESTABLISHEDWHICHSUGGESTS
THATHAVINGAMOREPHYSICALLYACTIVEPOPULATIONCOULDLOWERHEALTHCARECOSTS4HE
MAGNITUDESOFSUCHANEFFECTREMAINUNCLEARANDFEWDIRECTESTIMATESAREAVAILABLE
4HEBESTKNOWNESTIMATESTODATERELYONASSESSMENTSOFHEALTHEFFECTSATTRIBUTING
SHARES OF AVERAGE EXPENDITURE FOR SPECIlC DISEASES /THER RESEARCH COMPARES
ACTIVE AND INACTIVE PERSONS AT ONE POINT IN TIME CROSSSECTIONALLY SUGGESTING
THATPHYSICALLYINACTIVEPEOPLEHAVEHEALTHCAREEXPENDITURESTHATAREONAVERAGE
ABOUTONETHIRDABOVEMEDICALCOSTSOFACTIVEINDIVIDUALSORADIFFERENCEOF
INWHICHWOULDCORRESPONDTOIN!CROSSSECTIONALAPPROACH
ISPROBLEMATICBECAUSEITCANNOTCORRECTFORSELECTIONBIASTHATISPOORUNDERLYING
HEALTHCANSIMULTANEOUSLYCAUSEBOTHHIGHHEALTHCARECOSTSANDPHYSICALINACTIVITY
0ROSPECTIVELONGITUDINALDATAONHEALTHCARECOSTSCANREDUCESELECTIONBIASBUT
LONGITUDINALESTIMATESARESOFARAVAILABLEONLYFORMEMBERSINASINGLEHEALTHPLAN
ORFORSELECTEDEMPLOYERSRATHERTHANFORANATIONALSAMPLE
&ORHEALTHPLANSTRYINGTOMANAGEDISEASESITISALSOIMPORTANTTOKNOWHOW
PHYSICALACTIVITYMAYMODERATEFUTUREHEALTHCARECOSTSAMONGINDIVIDUALSWITHPRE
EXISTINGCONDITIONSLIKEHYPERTENSIONHEARTDISEASEORHEALTHRISKBEHAVIORSSUCHAS
!NDREYEVAISWITHTHE0ARDEE2!.$'RADUATE3CHOOL3ANTA-ONICA#!3TURMISWITH
THE2!.$#ORPORATION3ANTA-ONICA#!
3
0!AND0ROSPECTIVE(EALTH#ARE#OSTS 3
OBESITYORSMOKING0HYSICALACTIVITYMAYVERYWELLHAVEDIFFERENTIALEFFECTSACROSS
THESEGROUPSBUTNOCOMPARATIVEDATAAREAVAILABLEFORSPECIlCHEALTHCONDITIONS
OTHERTHANFORPATIENTSWITHARTHRITISANDWITHDEPRESSIVESYMPTOMS#OMPARING
THEEFFECTSOFPHYSICALACTIVITYACROSSSUBPOPULATIONSWOULDHELPHEALTHPLANSTO
MOREEFFECTIVELYTARGETHEALTHPROMOTIONRESOURCES
4HIS STUDY USED LONGITUDINAL DATA FROM A NATIONALLY REPRESENTATIVE SAMPLE
OFINDIVIDUALSAGETO(EALTHCARECOSTSWEREMEASUREDOVERYFOLLOWING
ANASSESSMENTOFREGULARPHYSICALACTIVITYWESHOWTHEANNUALAVERAGEANDWE
ADJUSTEDFORBASELINESOCIODEMOGRAPHICSHEALTHSTATUSHEALTHCARECOSTSANDHEALTH
RISKBEHAVIORS7EALSOSTRATIlEDTHEANALYSISBYBASELINEMEDICALCONDITIONAND
HEALTHBEHAVIORTOASSESSWHETHERPHYSICALACTIVITYHADDIFFERENTIALEFFECTSFORTHE
SUBGROUPSOFINDIVIDUALSWITHSPECIlCCHRONICDISEASESEGDIABETESORHEALTH
BEHAVIORSEGSMOKERS
$ATAAND-ETHODS
4HE(23ISANATIONALBIENNIALLONGITUDINALSURVEYOFINDIVIDUALSAGESTOAT
BASELINEANDTHEIRSPOUSESREGARDLESSOFAGEDESIGNEDTOSTUDYTHEISSUES
OFRETIREMENTHEALTHINSURANCESAVINGANDECONOMICWELLBEINGOFTHEPOPULATION
APPROACHINGTHERETIREMENTAGE4HESURVEYOVERSAMPLED(ISPANICSBLACKSAND
&LORIDARESIDENTSANDPROVIDEDWEIGHTINGVARIABLESTOMAKEITREPRESENTATIVEOFTHE
COMMUNITYBASEDPOPULATIONNATIONWIDE4HEINITIALPANELINCLUDED
AGEELIGIBLEPRIMARYRESPONDENTSATBASELINE&OLLOWUPSURVEYSWERECONDUCTEDBY
TELEPHONEINTERVIEWSINANDWITHPROXYINTERVIEWS
AFTERDEATH$ATAONTOTALHEALTHCARECOSTSWERENOTCOLLECTEDINTO
ANDWETHEREFOREUSEDTHELASTFOURWAVESWHICHINCLUDEDOBSERVATIONSON
INDIVIDUALS
4HESTUDYCOLLECTEDINFORMATIONABOUTDEMOGRAPHICSFAMILYSTRUCTUREHEALTH
COGNITIONFUNCTIONALLIMITATIONSHEALTHCAREUTILIZATIONANDEXPENDITURESINCOME
EMPLOYMENTSTATUSANDHISTORYHOUSINGINSURANCEANDEXPECTATIONSOFTHESURVEY
PARTICIPANTS4HEMOSTIMPORTANTADVANTAGESOFTHE(23DATAAREITSLONGITUDINAL
NATUREANDTHEFOCUSONTHELATEMIDDLEAGEGROUPˆAPOPULATIONATHIGHERRISKFOR
DEVELOPINGCHRONICHEALTHPROBLEMSANDFUNCTIONALLIMITATIONSTHANALLADULTS-ORE
INFORMATIONABOUTTHESURVEYANDITSDESIGNISAVAILABLEONTHE(23WEBSITEHTTP
HRSONLINEISRUMICHEDU
7EUSEDHEALTHCAREEXPENDITUREDATAFROMTHE(23lLESDEVELOPEDBY2!.$
AVAILABLETOREGISTERED(23USERSATHTTPHRSONLINEISRUMICHEDUDATAINDEXHTML
!STHEORIGINAL(23MEDICALEXPENDITUREDATAWERELIMITEDTOBRACKETINFORMATION
ONMEDICALSPENDINGANDCONTINUOUSVALUESWEREDERIVEDINACOMPLEXIMPUTATION
PROCESSWECOMPAREDTHE(23DATATOTHEEXPENDITUREDATAFROMOTHERNATIONAL
SOURCES 7E FOUND THAT OUR (23 AVERAGE EXPENDITURES WERE COMPARABLE WITH
ESTIMATES FOR THE SAME AGE GROUP FROM THE -EDICAL %XPENDITURE 0ANEL 3URVEY
-%03ACCOUNTINGFORTHEFACTTHAT(23USEDTOTALHEALTHCARECOSTSWHEREAS
-%03EXCLUDEDOVERTHECOUNTERMEDICATIONSORALTERNATIVECARESOURCES
7EIMPOSEDSEVERALSAMPLERESTRICTIONS&IRSTWEEXCLUDEDINDIVIDUALSWITH
FUNCTIONALLIMITATIONSBASEDONSELFREPORTEDDIFlCULTYWITHPERFORMINGANYOFTHE
lVEDIFFERENTTASKSINTHEACTIVITIESOFDAILYLIVING!$,BATHINGEATINGDRESSING
WALKINGACROSSAROOMANDGETTINGINOROUTOFBEDOFTHEORIGINALSAMPLE
3 !NDREYEVAAND3TURM
4HEIDEAOFTHISEXCLUSIONWASTOMITIGATEPOSSIBLESELECTIONBIASBYEXCLUDING
PEOPLEWHOSEPHYSICALACTIVITYISLIMITEDBECAUSEOFAPREEXISTINGHEALTHCONDI
TION)NDIVIDUALSWITH!$,LIMITATIONSWEREONAVERAGEMORETHANHALFLESSLIKELY
TOENGAGEINVIGOROUSPHYSICALACTIVITYTHANTHERESTOFTHESAMPLEANDHADSUBSTAN
TIALLYHIGHERHEALTHCARECOSTSSUPPORTINGOURASSUMPTIONTHATSELECTIONBIASWOULD
BEASIGNIlCANTPROBLEMHADWEKEPTTHISGROUPINTHEANALYSIS3ECONDWELEFT
OUTINDIVIDUALSWHENTHEYDIDNOTHAVEEXPENDITUREDATABETWEENTWOCONSECUTIVE
PERIODSOFTHEORIGINALSAMPLE7EREQUIREDEXPENDITUREDATAATCONSECUTIVE
PERIODSBECAUSEITALLOWEDUSTOIDENTIFYACHANGEINHEALTHCARECOSTSOVERTIME
4HISGROUPWASSLIGHTLYLESSPHYSICALLYACTIVEANDOLDERTHANTHERESTOFTHESAMPLE
3OME ADDITIONAL PARTICIPANTS WERE LOST TO FOLLOWUP OR DUE TO MISSING DATA ON
COVARIATESAROUNDOFTHEORIGINALSAMPLEYETTHISGROUPWASNOTSIGNIlCANTLY
DIFFERENTFROMTHESAMPLEONEITHERPHYSICALACTIVITYORHEALTHEXPENDITUREMEASURES
4HElNALEXCLUSIONOFTHEORIGINALSAMPLEWASFORDATAPROBLEMSSUCHAS
DISCREPANCIESINMEDICALSPENDINGANDUTILIZATIONDATAEGREPORTEDHEALTHCARE
UTILIZATIONBUTZEROHEALTHCAREEXPENDITURES!FTERALLEXCLUSIONSINDIVIDUALS
REMAINEDELIGIBLEFORANALYSISCONTRIBUTINGOBSERVATIONS
-EASURES
$EPENDENT6ARIABLES
4HEMAINDEPENDENTVARIABLEWASAVERAGEANNUALHEALTHCARECOSTSINmATEDTO
DOLLARSUSINGTHEMEDICALCARECOMPONENTOFTHECONSUMERPRICEINDEX7EUSEDTOTAL
RATHERTHANOUTOFPOCKETHEALTHCARECOSTSBECAUSEINOURAGEGROUPTHEMAJORITYOF
INDIVIDUALSHADINSURANCECOVERAGETHROUGHTHEIREMPLOYEROR-EDICAREANDOUT
OFPOCKETMEDICALCOSTSWOULDNOTGIVEACOMPLETEPICTUREOFEXPENDITURESRELATED
TOTHEIRHEALTHCARE7EASSESSEDTOTALHEALTHCARECOSTSOVERYAFTERMEASURING
PHYSICALACTIVITYHEALTHSTATUSANDOTHERCOVARIATES7EINCLUDEDBASELINEHEALTH
CARECOSTSASACOVARIATE!LTHOUGHEXPRESSEDINABSOLUTEDOLLARSINCLUDINGBASELINE
EXPENDITURESMADETHEMODELEQUIVALENTTOANALYZINGTHECHANGEINHEALTHCARE
EXPENDITURESASTHEDEPENDENTVARIABLE
%XPLANATORY6ARIABLES
4HE PRIMARY EXPLANATORY VARIABLE WAS A MEASURE OF REGULAR VIGOROUS PHYSICAL
ACTIVITYTHATWASBASEDONAhYESNOvRESPONSETOTHEQUESTIONh/NAVERAGEOVER
THELASTMONTHSHAVEYOUPARTICIPATEDINVIGOROUSPHYSICALACTIVITYOREXERCISE
THREETIMESAWEEKORMORE"YVIGOROUSPHYSICALACTIVITYWEMEANTHINGSLIKE
SPORTSHEAVYHOUSEWORKORAJOBTHATINVOLVESPHYSICALLABORv4HESURVEYASKED
INITIALLYMORECOMPREHENSIVEQUESTIONSABOUTTHETYPESOFPHYSICALACTIVITYINCLUD
INGLIGHTPHYSICALACTIVITYVIGOROUSPHYSICALACTIVITYDOINGHEAVYHOUSEWORKAND
THEFREQUENCIESINEACHOFTHESEACTIVITYCATEGORIES5NFORTUNATELYONLYTHEVIGOR
OUSACTIVITYQUESTIONWASAVAILABLEINTHESURVEYYEARSTHATCOLLECTEDDATAONTOTAL
HEALTHCARECOSTSTO
7EADJUSTEDFORDIFFERENCESINBASELINEHEALTHUSINGINDICATORSFOREIGHTSELF
REPORTEDDOCTORDIAGNOSEDCHRONICDISEASESASASSESSEDFROMRESPONSESTOTHEQUES
TIONhWHETHERORNOTADOCTOREVERTOLDTHERESPONDENTTHATHESHEHADTHECONDITIONSv
0!AND0ROSPECTIVE(EALTH#ARE#OSTS 3
4HESE EVEREXPERIENCED CHRONIC CONDITIONS WERE ARTHRITISRHEUMATISM DIABETES
CARDIOVASCULARDISEASEHYPERTENSIONLUNGDISEASECANCEREXCLUDINGMINORSKIN
CANCERSNERVOUSPSYCHIATRICPROBLEMSANDSTROKE7EALSOANALYZEDTHEMODEL
SPECIlCATIONSWITHALTERNATIVEMEASURESOFBASELINEHEALTHSUCHASANINDICATOROF
POORHEALTHANDASUBSETOFSELECTEDHEALTHCONDITIONSTOSEEHOWSENSITIVERESULTS
WERETOPARTIALADJUSTMENTSFORBASELINEDIFFERENCES
7EATTEMPTEDTOSEPARATETHEEFFECTOFPHYSICALACTIVITYONCHANGESINHEALTHCARE
EXPENDITUREFROMTHECONFOUNDINGEFFECTOFOBESITYBYEITHERINCLUDINGORSTRATIFYING
BYRELATIVEWEIGHTDISTINGUISHINGUNDERWEIGHT"-)NORMALWEIGHT"-)
TOOVERWEIGHT"-)TOMODERATEOBESITY"-)TO
SEVEREOBESITY"-)TOANDEXTREMEOBESITY"-)r4HEREARE
LARGEDIFFERENCESACROSSTHESEGROUPSINHEALTHCAREUTILIZATIONANDCOSTS
/THER EXPLANATORY VARIABLES WERE BASELINE HEALTH CARE EXPENDITURE GENDER
AGEAGEINYEARSANDTHESECONDORDERPOLYNOMIALOFAGERACEETHNICITYBLACK
(ISPANICOTHERWHITEISTHEREFERENCEINSURANCESTATUSPUBLICPRIVATEUNINSURED
ISTHEREFERENCEMARITALSTATUSMARRIEDDIVORCEDSEPARATEDWIDOWEDNEVERMAR
RIEDISTHEREFERENCEEDUCATIONCOLLEGESOMECOLLEGEHIGHSCHOOLLESSTHANHIGH
SCHOOLISTHEREFERENCEANNUALTOTALHOUSEHOLDINCOMEONTHELOGSCALEINmATED
TODOLLARSUSINGTHECONSUMERPRICEINDEXCENSUSREGIONANDSURVEYWAVE
DUMMIES4OACCOUNTFORTHEEFFECTSOFBEHAVIORALRISKFACTORSONCHANGESINHEALTH
CARECOSTSWEUSEDTOBACCOSMOKINGSTATUSCURRENTSMOKERANDPASTSMOKERAND
ALCOHOLUSEBASEDONCURRENTDIETARYGUIDELINESHEAVYDRINKINGWASDElNEDASMORE
THANONAVERAGEDRINKDAYFORWOMENANDALLINDIVIDUALSAGESANDABOVEAND
GREATERTHANDRINKSDAYFORMENBELOWAGEMODERATEDRINKINGWASDElNEDAS
ANAVERAGEOFDRINKDAYORLESSFORWOMENANDALLINDIVIDUALSOFAGESBELOW
ANDANAVERAGEOFDRINKSORLESSPERDAYFORMENAGESANDBELOW4ABLE
REPORTSDESCRIPTIVESTATISTICSOFTHESTUDYPARTICIPANTSBYPHYSICALACTIVITYSTATUS
4HETIMINGDESIGNOFOURMODELWASSUCHTHATWEMEASUREDALLEXPLANATORY
VARIABLESINTHEPERIODOFPHYSICALACTIVITYASSESSMENTWHILETHEMAINOUTCOME
WASAVERAGEANNUALHEALTHCARECOSTSYAFTERBASELINE!SASENSITIVITYANALYSIS
WEALSOANALYZEDAVERAGEANNUALHEALTHCARECOSTSANDYAFTERBASELINE
-ETHODS
7EPOOLEDTHE(23DATAACROSSTHEFOURWAVESWITHAVAILABLETOTALMEDICALEXPEN
DITURETOINCREASETHESAMPLESIZE!LLANALYSESACCOUNTEDFORTHECOMPLEXSAMPLING
DESIGNOFTHE(23USINGINFORMATIONONTHESURVEYWEIGHTSSTRATAANDPRIMARY
SAMPLINGUNITSASIMPLEMENTEDINSURVEYDATAESTIMATIONCOMMANDSIN3TATA
3TATA#ORP#OLLEGE3TATION484HE(UBER7HITENONPARAMETERICCORRECTIONWAS
USEDTOADJUSTSTANDARDERRORSFORREPEATEDOBSERVATIONSONTHESAMEINDIVIDUALS
4HEDEPENDENTVARIABLEHEALTHCAREEXPENDITUREWASREGRESSEDUSINGLEAST
SQUARESREGRESSIONONHEALTHCAREEXPENDITUREPHYSICALACTIVITYHEALTHSTATUSAND
OTHERCOVARIATESINTHEPREVIOUSSURVEYPERIOD4HEREWASNOADVANTAGEOFUSINGA
TWOPARTMODELINOURDATABECAUSETHELARGEMAJORITYINTHESAMPLEABOUT
USEDHEALTHCAREMULTIPARTMODELSIMPROVEPRECISIONBYSEPARATINGUSERSFROM
NONUSERS
"ASEDONSPECIlCATIONTESTSFORINTERACTIONSBETWEENPHYSICALACTIVITYHEALTH
CONDITIONSANDSOCIODEMOGRAPHICCOVARIATESWEDIDNOTINCLUDEANYINTERACTION
3 !NDREYEVAAND3TURM
4ABLE#HARACTERISTICSOF3TUDY0ARTICIPANTSBY0HYSICAL!CTIVITY3TATUS
3TUDYSAMPLE.
#HARACTERISTIC
0HYSICALACTIVITY
3AMPLE 0HYSICALLY 0HYSICALLY
INACTIVE
SIZE
ACTIVEA
0ARTICIPATEDINVIGOROUSPHYSICAL
ACTIVITYORMORETIMESWEEK
!RTHRITIS
"ACKPAIN
#ANCER
$IABETES
(EARTDISEASE
(YPERTENSION
,UNGDISEASE
0SYCHIATRICPROBLEMS
3TROKE
&EMALE
0ERYEARINDOLLARS
4OTALHEALTHCARECOSTS 0ERYEARINDOLLARS
#HRONICHEALTHCONDI
TIONS
'ENDER
!GEY
2ACEETHNICITY
%DUCATION
)NSURANCE
-ARITALSTATUS
3MOKING
!LCOHOLCONSUMPTION
"ODYMASSINDEXCLASS
&AMILYINCOME
A
9EARS
7HITE
"LACK
(ISPANIC
/THER
#OLLEGE
,ESSTHANCOLLEGE
(IGHSCHOOL
,ESSTHANHIGHSCHOOL
0RIVATE
0UBLIC
5NINSURED
-ARRIEDPARTNERSHIP
$IVORCED
7IDOWED
#URRENTSMOKING
0ASTSMOKING
(EAVYDRINKING
-ODERATEDRINKING
5NDERWEIGHT"-)
.ORMALWEIGHT"-)
/VERWEIGHT"-)
-ODERATEOBESITY"-)
3EVEREOBESITY"-)
%XTREMEOBESITY"-)r
.OTE 0ARTICIPATEDINVIGOROUSPHYSICALACTIVITYLIKESPORTSHEAVYHOUSEWORKORAJOBTHATINVOLVESPHYSICAL
LABORTIMESAWEEKORMOREOVERTHELASTMONTHS
$ATAAREPRESENTEDASPERCENTAGESUNLESSOTHERWISEINDICATED-EANSADJUSTEDFORTHECOMPLEXSURVEYDESIGN
0VALUESAREFORCOMPARISONOFMEANSBETWEENPHYSICALLYACTIVEANDINACTIVEINDIVIDUALS
0
0
0!AND0ROSPECTIVE(EALTH#ARE#OSTS 3
TERMS7EUSEDGENDERSPECIlCLINEARREGRESSIONTOESTIMATEDIFFERENTIALEFFECTSOF
PHYSICALACTIVITYBYGENDERBUTALLOTHERANALYSESWEREBASEDONESTIMATIONFOR
WOMENANDMENCOMBINED7EALSOCONDUCTEDSTRATIlEDANALYSESFORINDIVIDUALS
AGESOROLDERANDUNDERASWELLASRACEETHNICITYSPECIlCESTIMATIONBUT
THESEANALYSESWERELIMITEDBYSMALLSAMPLESIZESOFSOMEGROUPSEG(ISPANICS
AGEANDABOVE
!NOTHERSERIESOFESTIMATIONANALYSESWASBASEDONTHEVARIATIONINPREEXIST
INGHEALTHCONDITIONSANDHEALTHRISKS&IRSTWECOMPAREDHOWCHANGESINHEALTH
CARECOSTSDIFFEREDBYPHYSICALACTIVITYSTATUSAMONGPEOPLEWITHACERTAINCHRONIC
CONDITION7ECONSIDEREDALLREPORTEDMEDICALCONDITIONSREGARDLESSOFWHETHER
LINKSWITHPHYSICALACTIVITYHAVEBEENESTABLISHEDARTHRITISCANCERCARDIOVASCULAR
DISEASEDIABETESHYPERTENSIONLUNGDISEASEPSYCHOLOGICALPROBLEMSSTROKEAND
BACKPROBLEMS
4HENEXTSUBSAMPLEANALYSISCOMPAREDCHANGESINHEALTHCAREEXPENDITURES
RELATEDTOPHYSICALACTIVITYAMONGCURRENTSMOKERSCURRENTORPASTSMOKERS
ANDPEOPLEWHONEVERSMOKEDANDOBESEASDElNEDBY"-)OFANDABOVE
ANDNONOBESEINDIVIDUALS!SEPARATEANALYSISOFHEAVYDRINKERSWASLIMITEDBY
SAMPLESIZE&INALLYWECHECKEDTHEROBUSTNESSOFRESULTSTOTHEEXCLUSIONOFOUTLIERS
INHEALTHCAREEXPENDITURESTOPOFHEALTHEXPENDITUREDATAINACORRESPONDING
WAVE7HILESOMEEXTREMELYHIGHCOSTOBSERVATIONSANDTHEREWERESOMEINEXCESS
OFPERYEARCORRECTLYREmECTEDEXPENDITURESOTHERSWERETHERESULTOFDATA
ENTRYERRORS5NFORTUNATELYTHESETWOSITUATIONSWEREOFTENINDISTINGUISHABLE
2ESULTS
2EGULAR6IGOROUS0HYSICAL!CTIVITY
"EFOREWEAPPLIEDALLEXCLUSIONCRITERIATOOURANALYTICSAMPLEEGFUNCTIONALLY
LIMITEDPEOPLEABOUTOFTHETO(23SAMPLEREPORTEDBEINGVIGOR
OUSLYACTIVE4HISISSIMILARTOTHEAMONGADULTSAGESTOTHATSATISlED
GUIDELINESFORMODERATEPHYSICALACTIVITYINTHEMEDIANSTATEINTHE"EHAVIORAL
2ISK&ACTOR3URVEILLANCE3YSTEM"2&33ANDMUCHHIGHERTHANTHEWHO
SATISlEDTHEVIGOROUSACTIVITYGUIDELINESAMONGTOYEAROLDSINTHE
"2&33)NTHE%UROPEANANALOGUEOF(23THE3URVEYOF(EALTH!GEING
AND2ETIREMENTIN%UROPE3(!2%RESPONDENTSOFTHEEQUIVALENTAGEGROUP
REPORTEDPARTICIPATIONINSIMILARLYDElNEDVIGOROUSPHYSICALACTIVITYSPORTSHEAVY
HOUSEWORKORPHYSICALLABORMORETHANONCEAWEEKALTHOUGHTHEESTIMATESVARIED
FROMIN)TALYTOIN$ENMARK
4HEMAINREASONFORSUCHAHIGHPREVALENCEOFREGULARVIGOROUSPHYSICALACTIVITY
INTHE(23SAMPLEISTHATTHETOSURVEYSINCLUDEDOCCUPATIONALPHYSICAL
ACTIVITYINTHEMEASURE4HISSEEMEDTOALMOSTDOUBLEESTIMATESOFREPORTEDVIGOROUS
PHYSICALACTIVITYBECAUSEINTOWHENPHYSICALLABORWASNOTINCLUDEDIN
THEVIGOROUSACTIVITYQUESTIONONLYABOUTOFALLRESPONDENTSINDICATEDREGULAR
PARTICIPATIONINhVIGOROUSPHYSICALEXERCISEORSPORTSSUCHASAEROBICSRUNNING
SWIMMINGORBICYCLINGv
4HEPREVALENCEOFREGULARPHYSICALACTIVITYWASSIGNIlCANTLYLOWERFORINDIVIDU
ALSWITHANYOFTHEEIGHTCHRONICCONDITIONS4ABLESUGGESTINGTHATADJUSTMENT
3 !NDREYEVAAND3TURM
FORDIFFERENCESINBASELINEHEALTHWOULDREDUCESELECTIONORREVERSECAUSATIONBIAS
OFHEALTHSTATUSTHATAFFECTEDBOTHHEALTHCAREEXPENDITUREANDPHYSICALACTIVITY
ALTHOUGHWECANNEVERBESURETHATWEHAVEELIMINATEDIT
(EALTH#ARE%XPENDITURES
4ABLEREPORTSDESCRIPTIVEUNADJUSTEDANDPREDICTEDADJUSTEDAVERAGEANNUAL
HEALTHCAREEXPENDITURESBYPHYSICALACTIVITYSTATUSAMONGINDIVIDUALSAGESTO
,ACKOFREGULARPHYSICALACTIVITYWASASSOCIATEDWITHHIGHERHEALTHCARECOSTS
BOTHINACROSSSECTIONALANDLONGITUDINALSETTING$ESCRIPTIVELYTHEDIFFERENCEIN
HEALTHCARECOSTSRELATEDTOTHESAMEYEARPHYSICALACTIVITYWASORIN
DOLLARS0WHEREASACHANGEINHEALTHCARECOSTSYFROMTHEASSESS
MENTOFPHYSICALACTIVITYWASABOUTOR04HESEDESCRIPTIVE
ESTIMATESINCLUDEDTHEEFFECTSOFSOCIALANDHEALTHDIFFERENCESBETWEENACTIVEAND
INACTIVEGROUPS
!FTERADJUSTMENTFORBASELINEHEALTHCARESPENDINGSOCIODEMOGRAPHICSAND
POTENTIAL BEHAVIORAL CONFOUNDERS BUT NOT FOR BASELINE HEALTH THE DIFFERENCE IN
PROSPECTIVE HEALTH CARE COSTS RELATED TO PHYSICAL ACTIVITY DECLINED TO OR
0/URMOSTCOMPREHENSIVEADJUSTMENTWASTOCONTROLFOROBSERVED
4ABLE (EALTH#ARE#OSTSIN$OLLARS!MONG)NDIVIDUALS!GES
TOBY0HYSICAL!CTIVITY3TATUS
#ROSSSECTIONAL
,ONGITUDINAL
TWOYEARSFROMASSESSMENTOFPHYSICALACTIVITY
!DJUSTEDMEANS
BASELINEHEALTH
NOTINCLUDED
!DJUSTEDMEANS
BASELINEHEALTH
INCLUDED
#)
#)
5NADJUSTED
MEANS
#)
5NADJUSTED
MEANS
#)
.OREGULAR
PHYSICALACTIVITY
2EGULARPHYSI
CALACTIVITY
$OLLARDIFFER
ENCEFORPHYSI
CALINACTIVITY
DIFFERENCE
.OTE2EGULARPHYSICALACTIVITYISPARTICIPATIONINVIGOROUSPHYSICALACTIVITYLIKESPORTSHEAVYHOUSEWORK
ORAJOBTHATINVOLVESPHYSICALLABORTIMESAWEEKORMOREOVERTHELASTMONTHS#)ESTIMATESOFTHE
CONlDENCEINTERVALS$ATAARECORRECTEDFORTHECOMPLEXSURVEYDESIGN
%STIMATESOFHEALTHEXPENDITUREAREFORTHEPERIODOFPHYSICALACTIVITYISFORCROSS
SECTIONALANDLONGITUDINAL4HEREAREDIFFERENCESINTHEEXPENDITUREDATADUETOMISSINGVALUES
FORSOMEINDIVIDUALSACROSSWAVES
0REDICTEDAVERAGEHEALTHCARECOSTSHAVEBEENADJUSTEDFORBASELINEHEALTHCARECOSTSAGEGENDERRACEETHNICITY
FAMILYINCOMEEDUCATIONINSURANCEANDMARITALSTATUSCENSUSREGIONSURVEYWAVEBODYWEIGHTCLASSSMOK
INGANDDRINKING"ASELINEHEALTHISASSESSEDASASETOFEIGHTCHRONICCONDITIONS
0
00VALUESAREFORACOMPARISONOFMEANSBETWEENPHYSICALLYACTIVEANDINACTIVE
INDIVIDUALS
0!AND0ROSPECTIVE(EALTH#ARE#OSTS 3
DIFFERENCESINBASELINEHEALTHˆPOTENTIALCONFOUNDERSOFTHEABILITYTOBEPHYSICALLY
ACTIVEANDCONTRIBUTORSTOSELECTIONBIAS7ITHADJUSTMENTFORBASELINEHEALTHTHE
EFFECTSOFPHYSICALACTIVITYDECLINEDTOOR7HILETHISMAGNITUDEWAS
SUBSTANTIVELYIMPORTANTTHEEFFECTWASNOLONGERSTATISTICALLYSIGNIlCANT
'ENDERDIFFERENCESINTHEPREDICTEDCHANGESOFHEALTHCARECOSTSBYPHYSICAL
ACTIVITYAREREPORTEDIN4ABLE4HEPRESENTEDRESULTSWEREDRAWNFROMMODELSTHAT
ADJUSTEDFORBASELINEHEALTH4HEABSOLUTEDOLLARDIFFERENCESBETWEENACTIVEAND
INACTIVESUBPOPULATIONSWEREALMOSTIDENTICALFORMENANDWOMENALTHOUGHDUE
TOLOWERAVERAGECOSTSFORWOMENTHERELATIVEDIFFERENCERELATEDTOINACTIVITYWAS
LARGERFORWOMENTHANMEN4HECONlDENCEINTERVALSWEREWIDE
ANDTHEREWASNOSIGNIlCANTDIFFERENCEBETWEENMENANDWOMEN
4ABLE (EALTH#ARE#OSTS
IN$OLLARSBY0HYSICAL!CTIVITY
3TATUS'ENDER$IFFERENCES
-ALES
.
&EMALES
.
.OREGULARPHYSICALACTIVITY
2EGULARPHYSICALACTIVITY
$OLLARDIFFERENCEFORPHYSICALINACTIVITY
DIFFERENCE
.OTE2EGULARPHYSICALACTIVITYISPARTICIPATIONINVIGOROUSPHYSICALACTIVITYLIKESPORTSHEAVYHOUSEWORK
ORAJOBTHATINVOLVESPHYSICALLABORTIMESAWEEKORMOREOVERTHELASTMONTHS
#)ESTIMATESOFTHECONlDENCEINTERVALS$ATAARECORRECTEDFORTHECOMPLEXSURVEYDESIGN
0REDICTEDAVERAGEHEALTHCARECOSTSHAVEBEENADJUSTEDFORBASELINEHEALTHCARECOSTSCHRONICHEALTH
CONDITIONSAGEGENDERRACEETHNICITYFAMILYINCOMEEDUCATIONINSURANCEANDMARITALSTATUSCENSUS
REGIONSURVEYWAVEBODYWEIGHTCLASSSMOKINGANDDRINKING
4HERESULTSFROMSUBSAMPLEANALYSESFORHEALTHBEHAVIORSAREREPORTEDIN4ABLE
"ECAUSESAMPLESIZESWERESMALLERFORTHESUBGROUPCOMPARISONSIN4ABLES
ANDCOMPAREDTO4ABLECONlDENCEINTERVALSBECAMEEVENWIDERANDMOSTOF
THEDIFFERENCESWERENOTSTATISTICALLYSIGNIlCANT4HEPOINTESTIMATEOFCHANGESIN
HEALTHCARECOSTSRELATEDTOPHYSICALACTIVITYWASPARTICULARLYLARGEFOROBESEINDI
VIDUALSWHOHADONAVERAGEORABOUTLOWERFUTUREHEALTHCARECOSTSIF
THEYREGULARLYENGAGEDINVIGOROUSPHYSICALACTIVITY)NABSOLUTEMAGNITUDESTHIS
WASMUCHLARGERTHANTHEHEALTHCARECOSTDIFFERENCEBYPHYSICALACTIVITYINTHENON
OBESEPOPULATION3IMILARTOTHEOBESEGROUPWEFOUNDLARGERTHANAVERAGE
EFFECTSINTHEPOPULATIONOFCURRENTSMOKERSASWELLASINTHECOMBINED
SAMPLEOFCURRENTANDPREVIOUSREGULARSMOKERS4HOSESAVINGSWEREMORE
THANTWICETHEEFFECTOFPHYSICALACTIVITYAMONGNEVERSMOKERS
3TRATIFYINGBYPREEXISTINGHEALTHCONDITIONWEFOUNDHIGHERFUTUREHEALTHCARE
EXPENDITURESRELATEDTOBASELINEPHYSICALINACTIVITYACROSSMOSTCHRONICCONDITIONS
EXAMINED4ABLE%STIMATEDDIFFERENCESWEREPARTICULARLYLARGEFORBACKPAIN
3 !NDREYEVAAND3TURM
4ABLE (EALTH#ARE#OSTS
IN$OLLARSBY0HYSICAL!CTIVITY
3TATUS$IFFERENCESBY(EALTH2ISK
#URRENT
SMOKERS
0AST
CURRENT
SMOKERS
.EVER
.ONOBESE
SMOKED
. . . . .
/BESE
$OLLARDIFFERENCEFOR
PHYSICALINACTIVITY
DIFFERENCE
.OREGULARPHYSICAL
ACTIVITY
2EGULARPHYSICALACTIVITY
.OTE2EGULARPHYSICALACTIVITYISPARTICIPATIONINVIGOROUSPHYSICALACTIVITYLIKESPORTSHEAVYHOUSEWORK
ORAJOBTHATINVOLVESPHYSICALLABORTIMESAWEEKORMOREOVERTHELASTMONTHS#)ESTIMATESOFTHE
CONlDENCEINTERVALS$ATAARECORRECTEDFORTHECOMPLEXSURVEYDESIGN
0REDICTEDAVERAGEHEALTH CARE COSTS HAVE BEEN ADJUSTED FOR BASELINE HEALTH CARE COSTS CHRONIC HEALTH
CONDITIONSAGEGENDERRACEETHNICITYFAMILYINCOMEEDUCATIONINSURANCEANDMARITALSTATUSCENSUS
REGIONSURVEYWAVEBODYWEIGHTCLASSSMOKINGANDDRINKING
4ABLE (EALTH#ARE#OSTS
IN$OLLARSBY0HYSICAL!CTIVITY
3TATUS$IFFERENCESBY0RE%XISTING(EALTH#ONDITION
!RTHRITIS "ACKPAIN $IABETES (EARTDISEASE (YPERTENSION
. . . .
.
.OREGULARPHYSICAL
ACTIVITY
2EGULARPHYSICAL
ACTIVITY
$OLLARDIFFERENCEFOR
PHYSICALINACTIVITY
DIFFERENCE
.OTE2EGULARPHYSICALACTIVITYISPARTICIPATIONINVIGOROUSPHYSICALACTIVITYLIKESPORTSHEAVYHOUSEWORK
ORAJOBTHATINVOLVESPHYSICALLABORTIMESAWEEKORMOREOVERTHELASTMONTHS#)ESTIMATESOFTHE
CONlDENCEINTERVALS$ATAARECORRECTEDFORTHECOMPLEXSURVEYDESIGN
0REDICTEDAVERAGEHEALTHCARECOSTSHAVEBEENADJUSTEDFORBASELINEHEALTHCARECOSTSCHRONICHEALTHCON
DITIONSAGEGENDERRACEETHNICITYFAMILYINCOMEEDUCATIONINSURANCEANDMARITALSTATUSCENSUSREGION
SURVEYWAVEBODYWEIGHTCLASSSMOKINGANDDRINKING
ANDHEARTDISEASEANDSMALLERTHANAVERAGEEFFECTSFORDIABETESHYPERTENSIONAND
ARTHRITIS4HELARGESTDIFFERENCEBETWEENYHEALTHCAREEXPENDITURESOFPHYSICALLY
ACTIVE AND INACTIVE INDIVIDUALS WAS PREDICTED FOR PEOPLE WITH DOCTORDIAGNOSED
CARDIOVASCULARDISEASEONAVERAGEOR04HEEFFECTOFPEOPLE
WITHBACKPAINWASONAVERAGEOR07EWERECONCERNEDTHAT
SUCHLARGEEFFECTSIZESREmECTEDDIFFERENCESINTHESEVERITYOFTHEUNDERLYINGCONDI
TIONRATHERTHANUNBIASEDEFFECTSOFPHYSICALACTIVITY4HESAMPLESIZESFORPEOPLE
WITHSTROKELUNGDISEASECANCERANDPSYCHIATRICPROBLEMSWERETOOSMALLFORA
MEANINGFULANALYSISANDTHEREFOREWEDIDNOTREPORTTHEIRRESULTS
0!AND0ROSPECTIVE(EALTH#ARE#OSTS 3
4HEEFFECTOFPHYSICALACTIVITYONANNUALHEALTHCARECOSTSYAFTERBASELINE
WASSIMILARINMAGNITUDETOTHECHANGESOVERY$ESCRIPTIVELYTHEDIFFERENCEIN
HEALTHCARECOSTSACCORDINGTOBASELINEPHYSICALACTIVITYWAS0Y
FROMBASELINEAND0YAFTERTHEASSESSMENTOFPHYSICALACTIVITY
-ULTIVARIATE REGRESSION ANALYSIS PREDICTED A DIFFERENCE IN Y HEALTH CARE COSTS
OF0WITHOUTADJUSTMENTFORBASELINEHEALTHANDINTHEMODEL
THATINCLUDEDEIGHTCHRONICDISEASESASCONTROLSFORHEALTHSTATUS4HEMAGNITUDE
OFTHEPHYSICALACTIVITYEFFECTSFORYHEALTHCARECOSTSWASSMALLERTHANCHANGES
FORTHEYANDYPERIODWITHOUTHEALTHADJUSTMENTANDWITHHEALTH
CONTROLSINSIGNIlCANTINANYMODEL/NEEXPLANATIONFORTHESERESULTSISAMORE
LIMITEDSAMPLEWITHTHEEXPENDITUREDATAINTHELATERPERIODSOFTHESURVEYABOUT
OFOBSERVATIONSFROMTHEPRIMARYSAMPLEHADEXPENDITUREDATAOVERYAND
LESSTHANWEREAVAILABLETOESTIMATEHEALTHCARECOSTSYFROMBASELINE4HIS
ALSOPRECLUDEDRELIABLEESTIMATIONOFANDYHEALTHEXPENDITUREDATAFORMANY
SUBSAMPLEANALYSES
4ABLEPRESENTSESTIMATESFROMSENSITIVITYANALYSES7EEXPLOREDTHESENSI
TIVITYOFESTIMATESWITHALTERNATIVEMEASURESOFBASELINEHEALTHUSINGANINDICATOR
FORSELFREPORTEDPOORFAIRHEALTHSTATUSANDASUBSETOFCHRONICCONDITIONSSUCHAS
HEARTDISEASEANDDIABETES4HEMODELWITHPOORHEALTHSTATUSPREDICTEDADIFFER
ENCEOFINHEALTHCARECOSTSOFPHYSICALLYACTIVEANDINACTIVEPEOPLE
7HENWEUSEDBASELINEDIABETESANDHEARTDISEASEASPROXIESOFHEALTHSTATUSWE
FOUNDASIGNIlCANTCHANGEINHEALTHCARECOSTSRELATEDTOPHYSICALACTIVITYOFAN
AVERAGEOR4HISWASONLYSLIGHTLYLOWERTHANTHEEFFECTSOFPHYSICAL
ACTIVITYPREDICTEDBYMODELSWITHOUTADJUSTMENTFORBASELINEHEALTH&INALLYWE
TESTEDTHEROBUSTNESSOFOURESTIMATESTOTHEEXCLUSIONOFOUTLIERS4HEEXCLUSION
OFBOTTOMANDTOPHEALTHCARECOSTSASWELLASTOPLEFTTHEMAGNITUDE
OFTHEEFFECTSUNCHANGEDATABOUTTO
4ABLE(EALTH#ARE#OSTSIN$OLLARSBY0HYSICAL!CTIVITY3TATUS
3ENSITIVITY!NALYSIS
3ELFREPORTEDPOOR (EARTDISEASEAND
HEALTHASCONTROLFOR DIABETESASCONTROL TOP
TOPAND
BASELINEHEALTH
FORBASELINEHEALTH EXCLUDED BOTTOMEXCLUDED
. .
.
.
.OREGULARPHYSICAL
ACTIVITY
2EGULARPHYSICAL
ACTIVITY
$OLLARDIFFERENCEFOR
PHYSICALINACTIVITY
DIFFERENCE
.OTE2EGULARPHYSICALACTIVITYISPARTICIPATIONINVIGOROUSPHYSICALACTIVITYLIKESPORTSHEAVYHOUSEWORKORA
JOBTHATINVOLVESPHYSICALLABORTIMESAWEEKORMOREOVERTHELASTMONTHS#)ESTIMATESOFTHECONlDENCE
INTERVALS$ATAARECORRECTEDFORTHECOMPLEXSURVEYDESIGN
0REDICTEDAVERAGEHEALTHCARECOSTSHAVEBEENADJUSTEDFORBASELINEHEALTHCARECOSTSCHRONICHEALTHCONDITIONS
AGEGENDERRACEETHNICITYFAMILYINCOMEEDUCATIONINSURANCEANDMARITALSTATUSCENSUSREGIONSURVEYWAVE
BODYWEIGHTCLASSSMOKINGANDDRINKING
00VALUESAREFORACOMPARISONOFMEANSBETWEENPHYSICALLYACTIVEANDINACTIVEINDIVIDUALS
3 !NDREYEVAAND3TURM
$ISCUSSION
4HISSTUDYANALYZEDPROSPECTIVELYHOWPHYSICALACTIVITYWASASSOCIATEDWITHCHANGES
INHEALTHCAREEXPENDITURESINANATIONALLYREPRESENTATIVESAMPLEOFADULTSAGETO
Y4HISAGEGROUPISATHIGHRISKOFINCREASEDHEALTHCAREEXPENDITURESBECAUSE
OFTHEONSETOFCHRONICMEDICALPROBLEMSTHATCOULDBEDELAYEDORPREVENTEDWITH
PHYSICALACTIVITY7EFOUNDTHATAMONGADULTSAGESTOWITHOUTFUNCTIONAL
LIMITATIONSLACKOFREGULARPHYSICALACTIVITYWASASSOCIATEDWITHANAVERAGE
INCREASEINTOTALHEALTHCARECOSTSOVERYORINDOLLARSALTHOUGHA
CONlDENCEINTERVALINCLUDEDTHEPOSSIBILITYOFNOEFFECT4HEABSOLUTEMAGNITUDE
WASSIMILARFORMENANDWOMEN
#HANGESINHEALTHCARECOSTSRELATEDTOPHYSICALACTIVITYVARIEDSUBSTANTIALLY
ACROSSPEOPLEWITHDIFFERENTHEALTHRISKSORCHRONICCONDITIONS4HISINFORMATION
REMAINSHIDDENINTHEAVERAGEEFFECTSOFPHYSICALACTIVITYBUTWOULDBEIMPORTANT
FORHEALTHPLANSTARGETINGHEALTHPROMOTIONRESOURCES3TRATIFYINGBYRISKBEHAVIOR
WEFOUNDTHATPHYSICALACTIVITYWASPARTICULARLYBENElCIALTOLOWERHEALTHCARECOSTS
OFSMOKERSANDOBESEINDIVIDUALS2EGULARPHYSICALACTIVITYMIGHTHELPREDUCESOME
OFTHEEXCESSHEALTHCARECOSTSINTHEOBESEPOPULATIONALTHOUGHEVENPHYSICALLY
ACTIVEOBESEINDIVIDUALSSTILLHADONAVERAGEALMOSTHIGHERMEDICAL
COSTSTHANNONOBESEPHYSICALLYINACTIVEINDIVIDUALS2ESULTSFORSPECIlCCHRONIC
CONDITIONSSHOWEDVERYLARGEPOSITIVEEFFECTSOFPHYSICALACTIVITYONPEOPLEWITH
BACKPAINORHEARTDISEASEALTHOUGHWEWERECONCERNEDTHATTHELARGEESTIMATES
REmECTEDSOMEUNADJUSTEDSEVERITYOFBASELINECONDITIONS
7HEN REPLICATING THE APPROACH OF PRIOR CROSSSECTIONAL ANALYSIS WE FOUND
MUCHLARGERABSOLUTEDIFFERENCESINHEALTHCARECOSTSBYPHYSICALACTIVITYFORTHIS
AGEGROUPVSESTIMATESPUBLISHEDFORTHEFULLAGERANGEOFIN
DOLLARSINDOLLARS4HISISNOTSURPRISINGASLATEMIDDLEAGEADULTSARE
ATPARTICULARLYHIGHRISKFORDEVELOPINGCHRONICHEALTHPROBLEMSANDEXPERIENCE
INCREASESINHEALTHCARECOSTSOVERTIME(IGHERCROSSSECTIONALEFFECTSASSOCIATED
WITHPHYSICALACTIVITYINOURSAMPLEMAYALSOREmECTHEALTHBENElTSASSOCIATEDWITH
PHYSICALACTIVITYTHATHAVEBEENACCUMULATEDOVERALONGERLIFESPAN
/BSERVATIONAL CROSSSECTIONAL DATA ARE MORE LIKELY TO REmECT THE EFFECTS OF
REVERSECAUSALITYFROMHEALTHSTATUSTOPHYSICALACTIVITY)NDIVIDUALSHOSPITALIZEDFOR
PROLONGEDPERIODSHAVEEXTREMELYHIGHHEALTHCARECOSTSYETBYDElNITIONTHEYARE
ALSOPHYSICALLYINACTIVEDURINGTHATPERIOD"ECAUSEPHYSICALACTIVITYPATTERNSCAN
CHANGERAPIDLYCROSSSECTIONALESTIMATESAREMUCHMOREVULNERABLETOSELECTION
BIASTHANCORRESPONDINGESTIMATESOFTHEEFFECTSOFOBESITYWHICHTENDSTOREmECT
AMORELONGTERMINDIVIDUALCHARACTERISTICRELATEDTOGENETICSDIETANDPHYSICAL
ACTIVITY"IASESFROMPOORHEALTHAREALSOMORELIKELYTOOPERATETHEOPPOSITEWAY
IEUNDERESTIMATETHEEFFECTSOFOBESITYINCROSSSECTIONALDATAINTHATINDIVIDUALS
THATHADBEENDIAGNOSEDWITHDIABETESHYPERTENSIONORHEARTDISEASEINTHEPAST
MAYSTARTTOLOSEWEIGHTASPARTOFTHETREATMENT
7HEN ONLY PARTIALLY CONTROLLING FOR BASELINE HEALTH AS SOME PREVIOUS PRO
SPECTIVESTUDIESDIDWEFOUNDLARGEREFFECTS&OREXAMPLEASTUDYOFONEGROUPOF
HEALTHPLANENROLLEESAGESOROLDERSUGGESTEDTHATEACHACTIVEDAYPERWEEKIS
ASSOCIATEDWITHLOWERMEDIANHEALTHCARECHARGESOVERMONTHSFROMAN
ASSESSMENTOFPHYSICALACTIVITYORTOUSINGTHEAVERAGENUMBEROFACTIVE
DAYS7HENWEUSEDASIMILARAPPROACHWEOBTAINEDDATANOTPRESENTED
0!AND0ROSPECTIVE(EALTH#ARE#OSTS 3
PROBABLYAREmECTIONOFOUROLDERSAMPLE(OWEVERTHEPARTIALADJUSTMENTLEFTMUCH
OFTHESELECTIONBIASBETWEENCOMPAREDGROUPSANDCOULDNOTBEINTERPRETEDASA
GOODESTIMATEOFTHESHORTTERMEFFECTSOFPHYSICALACTIVITYONHEALTHCARECOSTS!T
THESAMETIMEITWASNOTANESTIMATEOFTHELONGTERMEFFECTSEITHERBECAUSEPAST
INACTIVITYMAYHAVECONTRIBUTEDTOSOMEOFTHECONTROLLEDHEALTHCONDITIONS
!DJUSTING ESTIMATES FOR DIFFERENCES IN BASELINE HEALTH BETWEEN PHYSICALLY
ACTIVE AND INACTIVE SUBPOPULATIONS CHANGED THE MAGNITUDE OF PHYSICAL ACTIVITY
EFFECTS DRAMATICALLY TO LESS THAN OF WHAT UNADJUSTED LONGITUDINAL COMPARI
SONSORALMOSTOFDESCRIPTIVECROSSSECTIONALCOMPARISONS4HISMAYINDICATE
THEEXTENTOFSELECTIONBIAS)TREMAINSANOPENQUESTIONHOWWELLWEMEASURED
BASELINEHEALTHANDHOWMUCHRESIDUALBIASESWERESTILLRETAINEDINOURESTIMATES
7EWERECERTAINLYCLOSERTOESTIMATINGTHECAUSALEFFECTOFHOWPHYSICALACTIVITY
CHANGESHEALTHCARECOSTSOVERYTHANSTUDIESLEAVINGOUTBASELINEDIFFERENCESIN
HEALTH7EBELIEVEOURESTIMATESINTHETORANGEORALMOSTPERYEARARE
SUBSTANTIVELYLARGEANDPROVIDEAMORECREDIBLEBASISFORASSESSINGTHEPOTENTIAL
EFFECTSOFPHYSICALACTIVITYINTERVENTIONSTHANASSUMINGTHATPHYSICALACTIVITYCOULD
REDUCESHORTTERMHEALTHCARECOSTSBY,IFECYCLEEFFECTSMAYVERYWELLBE
MUCHLARGERTHANOURSHORTTERMESTIMATESBECAUSETHEYWOULDINCLUDETHEEXTENT
TOWHICHPHYSICALINACTIVITYINTHEPASTHADCONTRIBUTEDTODEVELOPMENTOFHEALTH
CONDITIONSOBSERVEDATBASELINE,IFECYCLEEFFECTSAREHOWEVERHARDTOESTIMATE
WITHOUTLONGITUDINALDATAONINDIVIDUALSOVERSEVERALDECADES
4HISPAPERALSOHIGHLIGHTSACOMMONPROBLEMWITHSTUDYINGHEALTHCARECOSTS
INAGENERALPOPULATION4HEREAREMANYFACTORSOTHERTHANPHYSICALACTIVITYTHAT
AFFECTHEALTHCARECOSTSANDEVENIFTHESEFACTORSAREUNCORRELATEDWITHPHYSICAL
ACTIVITYTHEADDITIONALVARIATIONREDUCESTHEPRECISIONOFSTATISTICALESTIMATESESPE
CIALLYFORDEPENDENTVARIABLESSUCHASHIGHLYSKEWEDHEALTHCARECOSTS!LTHOUGH
OURPOINTESTIMATESMAYBESUGGESTIVETHELIMITEDPRECISIONALSOMEANSTHATTHEY
SHOULDNOTBEOVERINTERPRETED!MUCHLARGERTHANUSUALSAMPLESIZEISNECESSARY
TOGETREASONABLEPRECISIONINHEALTHCAREEXPENDITUREDATAWHICHISHIGHLYSKEWED
ANDNOISY6ERYFEWSTUDIESINCLUDINGOURSHADSUFlCIENTSAMPLESIZESTORELIABLY
MEASURESMALLEFFECTSIZES4HISHASRESULTEDINMANYUNREPORTEDNULLlNDINGS
ANDDUETOPUBLICATIONBIASTHATFAVORSSTATISTICALLYSIGNIlCANTRESULTSPUBLICATIONS
EXAGGERATINGTRUEEFFECTS7ENEEDTOGUARDAGAINSTTHISPROBLEMBECAUSEEXAGGER
ATEDEXPECTATIONSABOUTPHYSICALACTIVITYINTERVENTIONSWILLONLYRESULTINDISAP
POINTMENTSTHATAREDETRIMENTALTOTHELONGTERMPROMOTIONOFPHYSICALACTIVITY/UR
ESTIMATESEVENTHOUGHSMALLERTHANEARLIERESTIMATESANDSTATISTICALLYINSIGNIlCANT
ARESUBSTANTIVELYIMPORTANTTOHEALTHPLANS"UTTOMOREPRECISELYMEASURESMALL
EFFECTSVERYLARGESAMPLESIZESARENEEDEDANDTHEAVAILABILITYOFSUCHDATAWILLBE
ALIMITATIONFORTHEFORESEEABLEFUTURE
!MONGOTHERIMPORTANTSTUDYLIMITATIONSARETHECRUDENESSOFTHEPHYSICAL
ACTIVITYMEASUREWHICHDIDNOTPERMITTOCHARACTERIZEINTENSITYDURATIONOFACTIV
ITYORENERGYEXPENDITUREANDEVALUATEDAMONTHPERIODBEFORETHEINTERVIEW
4HATREGULARBRISKWALKINGAPPARENTLYTHEMOSTCOMMONFORMOFPHYSICALACTIVITY
INOURAGEGROUPDIDNOTQUALIFYUNDERTHESURVEYDElNITIONOFVIGOROUSACTIVITY
MEANSTHATWEMAYHAVEUNDERESTIMATEDTHEEFFECTSOFPHYSICALACTIVITYONCHANGES
INHEALTHCAREEXPENDITUREAMONGLATEMIDDLEAGEADULTS4HESHORTRUNEFFECTS
YINTHEMAINPARTUPTOYINSENSITIVITYANALYSESALSODIDNOTCAPTURETHETOTAL
LIFECYCLEEFFECTSOFPHYSICALACTIVITY&INALLYREGARDLESSOFHOWEXTENSIVELYWETRIED
3 !NDREYEVAAND3TURM
TOCONTROLFORBASELINEDIFFERENCESBETWEENACTIVEANDINACTIVEPEOPLEOURMEASURES
OFBASELINEHEALTHDIDNOTCAPTUREALLDIFFERENCESINTHESEVERITYOFTHEBASELINEHEALTH
CONDITIONSANDTHEPERSONSABILITYTOENGAGEINPHYSICALACTIVITY4HELONGITUDINAL
DESIGNREDUCEDSOMETYPESOFSELECTIONBIASESBUTDIDNOTGUARANTEETHATANYOFTHE
ESTIMATESREmECTEDTHECAUSALRELATIONSHIPTHATDECISIONMAKERSAREINTERESTEDIN
.EVERTHELESSTHISSTUDYPROVIDESNEWINFORMATIONABOUTTHEROLEOFPHYSI
CALACTIVITYFORCHANGESINHEALTHCAREEXPENDITURES&ROMAPOLICYPERSPECTIVE
THE POPULATION WE STUDIEDˆPEOPLE NEARING RETIREMENT AGE AND THOSE RECENTLY
RETIREDˆMERITSPECIALATTENTIONFORIMPLICATIONSOFTHEIRTRANSITIONINTO-EDICARE
AND3OCIAL3ECURITYPROGRAMS0HYSICALINACTIVITYMAYIMPOSEANOTICEABLEBURDEN
ON THE HEALTH CARE SYSTEM AND THIS BURDEN MAY BE PARTICULARLY LARGE FOR SOME
POPULATIONSUBGROUPSLIKESMOKERSANDOBESEINDIVIDUALS
)T IS IMPORTANT TO GET CREDIBLE POINT ESTIMATES YET PUBLICATION BIASES MAY
ENCOURAGEINmATEDESTIMATESOFTHEEFFECTSOFPHYSICALACTIVITYJUSTBECAUSETHEY
ARESTATISTICALLYSIGNIlCANT7HILESMALLERESTIMATEDEFFECTSMAYNOTHAVETHESAME
IMMEDIATEPOLICYAPPEALASPROMISESOFDRAMATICCOSTSAVINGSBROKENPROMISESDO
NOTFURTHERTHECAUSEOFPHYSICALACTIVITYINTERVENTIONSINTHELONGRUN
2EFERENCES
#OLDITZ '! %CONOMIC COSTS OF OBESITY AND INACTIVITY -ED 3CI 3PORTS %XERC
SUPPL3
+EELER%"-ANNING7'.EWHOUSE*03LOSS%-7ASSERMAN*4HEEXTERNALCOSTS
OFASEDENTARYLIFESTYLE!M*0UBLIC(EALTH
+ATZMARZYK04'LEDHILL.3HEPHARD2*4HEECONOMICBURDENOFPHYSICALINACTIVITY
IN#ANADA#-!*
0RATT--ACERA#!7ANG'(IGHERDIRECTMEDICALCOSTSASSOCIATEDWITHPHYSICAL
INACTIVITY0HYS-ED
0RONK.0'OODMAN-*/#ONNOR0*-ARTINSON"#2ELATIONSHIPBETWEENMODIl
ABLEHEALTHRISKSANDSHORTTERMHEALTHCARECHARGES*!-!
-ARTINSON"##RAIN!,0RONK.0/#ONNOR0*-ACIOSEK-6#HANGESINPHYSICAL
ACTIVITYANDSHORTTERMCHANGESINHEALTHCARECHARGESAPROSPECTIVECOHORTSTUDYOF
OLDERADULTS0REV-ED
'OETZEL2!NDERSON$7HITMER2/ZMINKOWSKI2$UNN27ASSERMAN*2ELA
TIONSHIP BETWEEN MODIlABLE HEALTH RISKS AND HEALTH CARE EXPENDITURES AN ANALYSIS
OFTHEMULTIEMPLOYER(%2/HEALTHRISKANDCOSTDATABASE*/CCUP%NVIRON-ED
7ANG&-C$ONALD4#HAMPAGNE,*%DINGTON$72ELATIONSHIPOFBODYMASSINDEX
ANDPHYSICALACTIVITYTOHEALTHCARECOSTSAMONGEMPLOYEES*/CCUP%NVIRON-ED
7ANG'"ROWN$2)MPACTOFPHYSICALACTIVITYONMEDICALEXPENDITURESAMONGADULTS
DOWNHEARTEDANDBLUE!M*(EALTH"EHAV
7ANG'(ELMICK#'-ACERA#:HANG00RATT-)NACTIVITYASSOCIATEDMEDICALCOSTS
AMONG53ADULTSWITHARTHRITIS!RTHRITIS2HEUM
(EERINGA 3' #ONNOR *( 4ECHNICAL DESCRIPTION OF THE HEALTH AND RETIREMENT
SURVEYSAMPLEDESIGN5NIVERSITYOF-ICHIGAN!NN!RBOR!VAILABLEATHTTP
HRSONLINEISRUMICHEDUDOCSSAMPLEHRS(233!-0PDFACCESSED&EB
-%03 #ENTER FOR #OST AND &INANCING 3TUDIES!GENCY FOR (EALTHCARE 2ESEARCH
AND 1UALITY -EDICAL %XPENDITURE 0ANEL 3URVEY !VAILABLE AT HTTP
WWWMEPSAHRQGOVLASTACCESSEDON&EBRUARY
0!AND0ROSPECTIVE(EALTH#ARE#OSTS 3
!NDREYEVA43TURM22INGEL*3-ODERATEANDSEVEREOBESITYHAVELARGEDIFFERENCES
INHEALTHCARECOSTS/BES2ES$EC
#$#.ATIONAL#ENTERFOR#HRONIC$ISEASE0REVENTIONAND(EALTH0ROMOTION!LCOHOL
AND0UBLIC(EALTHHTTPWWWCDCGOVALCOHOLFAQSHTMLASTACCESSED&EBRUARY
.)!!!(ELPINGPATIENTSWITHALCOHOLPROBLEMS!HEALTHPRACTITIONERSGUIDEHTTP
WWWNIAAANIHGOVPUBLICATIONS0RACTITIONER(ELPING0ATIENTSHTMSTEP! LAST
ACCESSED&EBRUARY
.ATIONAL #ENTER FOR #HRONIC $ISEASE 0REVENTION AND(EALTH0ROMOTION"EHAVIORAL
2ISK &ACTOR 3URVEILLANCE 3URVEY !VAILABLE AT HTTPAPPSNCCDCDCGOVBRFSS
DISPLAYASPCAT0!YRQKEYSTATE53 LAST ACCESSED ON 3EPTEMBER
3URVEYOF(EALTH!GEINGAND2ETIREMENTIN%UROPE%UROPE-ANMHEIM2ESEARCH
)NSTITUTEFORTHE%CONOMICSOF!GING
3TURM25NÓTZER*+ATON7%FFECTIVENESSRESEARCHANDIMPLICATIONSFORSTUDYDESIGN
SAMPLESIZEANDSTATISTICALPOWER'EN(OSP0SYCHIATRY
Download