cardiovascular disease steps to a healthy heart
TRANSCRIPT
CARDIOVASCULAR DISEASE
STEPS TO AHEALTHY HEART
A global partnership to promote walking
bupa.com/heart world-heart-federation.org
2
CONTENTS
2
Acknowledgements 2
Foreword 3
TheglobalburdenofCVD 4
Theimportanceofphysicalactivity 5
Physicalactivityrecommendations 6
Thebenefitsofwalking 8
Theneedforcollaborativeaction 10
AbouttheWorldHeartFederation 11
AboutBupa 13
References 14
ACKNOWLEDGEMENTS
BupaandtheWorldHeartFederationwouldliketothankKatyCooperfromC3Collaboratingfor
Health,andtheWorldHeartFederation’sChiefScienceOfficer,ProfessorKathrynTaubert,fortheir
valuableassistanceandfeedbackinthepreparationofthisreport.
3
Cardiovasculardisease(CVD),whichincludesheartdiseaseandstroke,isoneofthetoughestchallengesinhealthcare.Globally,morepeoplediefromCVDthanfromanyothercause.In2008,CVDclaimed17.3millionlivesand,by2030,itisexpectedthatnumberwillincreasetoover23million.
YetalargeproportionofillnessanddeathfromCVDcouldbepreventedifpeoplearoundtheworldwereabletobettermanagesimplelifestyleriskfactorsby,forexample,notsmoking,eatingwelland,importantly,doingmorephysicalactivity.
BupaandtheWorldHeartFederationarecommittedtogettingpeoplearoundtheworldtodomorephysicalactivitytolowertheirriskofCVD,sothatpeoplecanlivelonger,healthier,happierlives.
TheWorldHealthOrganization(WHO)estimatesthatmorethan60%ofpeoplearoundtheworldare
notsufficientlyactive,andphysicalinactivityisthefourthleadingriskfactorforglobalmortality.
That’swhyBupaandtheWorldHeartFederationarelaunchinganewpartnershiptogettheworldwalking.Walkingisthemostaccessibleformofphysicalactivity:it’sfree,mostpeoplecandoit,itcanbeeasilyincorporatedintoadailyroutineandit’sclinicallyproventhatitcanimproveaperson’shearthealth.
InordertosignificantlyreducethenumberofpreventabledeathsfromCVD,weallneedtoworktogethertosupportandmotivatepeopleacrosstheworldtotakestepstolowertheirrisk.
Wehaveasharedvisionandpurposetoimprovetheworld’shealthandweareproudtobeworkingtogethertomotivatepeopletotakestepstoahealthyheart.Wehopethattheworldjoinsusonourjourney.
FOREWORD
Stuart Fletcher Chief Executive Officer Bupa
Johanna RalstonChief Executive OfficerWorld Heart Federation
4
Cardiovasculardisease(CVD)isoneofthetoughestchallengesinhealthcare.Globally,morepeopledieeachyearfromCVDthanfromanyothercause.1
In2008,CVDclaimed17.3millionlives,accountingforonethirdofalldeathsfromallcauses,globally2andnearlyhalfoftheglobalnon-communicablediseaseburden,takingaterribletollonindividuals,familiesandsociety.3
By2030,itisexpectedthatthenumberofpeoplewhowilldiefromCVD(mainlyfromheartdiseaseandstroke)willincreaseto23.3million.4Yet,alargeproportionofdeathsfromCVDareavoidableandthereareanumberofwaysthatpeoplecanreducetheirrisk.5
AlthoughsomeCVDriskfactors,suchasfamilyhistoryorage,cannotbe
modified,80%ofallheartdiseaseandstrokewouldbepreventedifthemainriskfactorswereeliminated:ifweallstoppedsmoking,ateahealthydietanddidenoughphysicalactivity.6
TheprevalenceofCVDriskfactors(suchasphysicalinactivity)isincreasinginmostcountriesaroundtheworld7andthemoreriskfactorsapersonhas,thegreatertheirchanceofdevelopingthedisease.CVDriskfactorsthatcanbemodifiedortreatedincluderaisedbloodpressure(hypertension),raisedbloodglucose(diabetes),raisedbloodcholesterol,tobaccouse,physicalinactivity,andoverweightandobesity.8
Thegoodnewsisthat,formostCVDriskfactors,therearestepsyoucantaketoreducethem.
THE GLOBAL BURDEN OF CVD
What is CVD?
CVDiscausedbydisordersoftheheartandbloodvessels,andincludescoronaryheartdisease(heartattacks),cerebrovasculardisease(stroke),raisedbloodpressure(hypertension),peripheralarterydisease,rheumaticheartdisease,congenitalheartdiseaseandheartfailure.
CVDcanleadtoacuteeventssuchasheartattackorstroke,ormaycauselong-termhealthcomplicationsthatcanaffectmanypartsofaperson’slife,fromtheirabilitytoworkandhaverelationships,tohousingandeducationopportunities.
Heartattacksandstrokesareusuallyacuteeventsandaremainlycausedbyablockagethatpreventsbloodfromflowingtotheheartorbrain.Themostcommonreasonforthisisabuild-upofcholesterolandotherfattydeposits(calledplaque)ontheinnerwallsofthearteriesthatsupplytheheartorbrain.Thisbuild-updevelopsoveryears.Atsomepoint,aplaquecansuddenlyrupture,whichcausesabloodclottoformintheartery,cuttingoffbloodflowtoapartoftheheartorbrainandcausingaheartattackorastroke.Whilethemajorityofstrokesarecausedbybloodclots(ischemicstroke),somecanalsobecausedbyaburstbloodvesselinthebrain(hemorrhagicstroke).
5
Physicalinactivityisthefourthleadingriskfactorforglobalmortality(behindhighbloodpressure,tobaccouseandhighbloodglucose),andisakeyriskfactorforCVD9-beingphysicallyinactiveincreasesaperson’sriskofhavingaheartattackorstroke.10
Theimportanceofphysicalinactivityasariskfactorwasparticularlyrecognisedin2013whentheWorldHealthAssembly-theannualgatheringoftheworld’shealthministers-madeaglobalcommitmenttoreducetheprevalenceofinsufficientphysicalactivityby10%,asapartofasuiteoftargetsthataimtoreduceprematuremortalityfromnon-communicablediseases(NCDs)by25%by2025.
Despitetheknownhealthbenefitsofphysicalactivity,peopleinmanycountriesarebecominglessactive.Insomecases,thisisbecausetheenvironmentmakesithardertobuildexerciseintodailyroutines(forexample,ifitiseasiertotakethecarthantowalk),orbecausepeople’sjobsandlifestylesarebecominglessphysicallydemanding.ThiscanhavemajorimplicationsfortheprevalenceofNCDsandthegeneralhealthofpeoplearoundtheworld.11
AccordingtotheWHO,morethan60%oftheglobalpopulationarenotsufficientlyactive.12In2008,around31%ofadults(28%ofmenand34%ofwomen),aged15orolder,wereinsufficientlyactive.13
PrevalenceofinsufficientphysicalactivitywashighestintheWHORegionoftheAmericasandtheEasternMediterraneanRegion.Inboththeseregions,almost50%ofwomenwereinsufficientlyactive,whiletheprevalenceformenwas40%intheAmericasand36%inEasternMediterranean.TheSouthEastAsianRegionshowedthelowestpercentages(15%formenand19%forwomen).14
High-incomecountrieshavemorethandoubletheratesofinsufficientphysicalactivitycomparedtolow-incomecountriesforbothmenandwomen,with41%ofmenand48%ofwomenbeinginsufficientlyphysicallyactiveinhigh-incomecountriescomparedto18%ofmenand21%ofwomeninlow-incomecountries.15Inaddition,peopleindifferentsocioeconomicgroupshavedifferentpatternsofphysicalactivity–inEngland,forexample,peopleinhighersocioeconomicgroupsaremorelikelytoreachtherecommendedphysicalactivitylevels.16
THE IMPORTANCE OF PHYSICAL ACTIVITY
More than 60% of the
global population are
not sufficiently active
6
PHYSICAL ACTIVITY RECOMMENDATIONS
Differentagegroupshavedifferentphysicalactivityrequirements.17
Itisrecommendedthatchildrenandyoungpeopleshouldaccumulateatleast60minutesofmoderatetovigorous-intensityphysicalactivitydaily.Mostofthedailyphysicalactivityshouldbeaerobicactivities;andactivitiesthatstrengthenmuscleandboneshouldbeincluded,atleastthreetimesperweek.
Forchildrenandyoungpeopleaged5-17yearsold,physicalactivityincludesplay,games,sports,transportation,recreation,physicaleducationorplannedexercise,inthecontextoffamily,school,andcommunityactivities.
Adultsshoulddoatleast150minutesofmoderate-intensity(oratleast75minutesofvigorous-intensity)aerobicphysicalactivitythroughouttheweek,oranequivalentcombinationofmoderateandvigorous-intensityactivity.Aerobicactivityshouldbeperformedinboutsofatleast10minutesinduration,andmuscle-
strengtheningactivitiesthatinvolvemajormusclegroupsshouldbedoneontwoormoredayseachweek.
Whenadultsover65yearsoldcannotdotherecommendedamountsofphysicalactivityduetohealthconditions,theyshouldbeasphysicallyactiveastheirmobilityandhealthallow.
Physicalactivityforadultsincludesrecreationalorleisure-timephysicalactivity,transportation(e.g.walkingorcycling),occupational(i.e.work),householdchores,games,sportsorplannedexercise,inthecontextofdaily,family,andcommunityactivities.
DoingsomephysicalactivityisbetterthandoingnoneandevensmallincreasesinphysicalfitnessareassociatedwithasignificantreductioninCVDrisk.Inactiveadults,olderadultsandthosewithdiseaselimitationsreceiveaddedhealthbenefitswhentheybecomemoreactive.19
Adults should do at least 150
minutes of moderate physical
activity per week
7
Ifyou’renotusedtophysicalactivity,even30minutesmightsoundlikealot-butyoudonotneedtodoyour30minutesinonesession,20inactivepeopleshouldstartwithsmallamountsofphysicalactivityandgraduallyincreaseduration,frequencyandintensityovertime.
Youcanstartbymakingasmallchangesuchasensuringyougetupandmovearoundmorethroughouttheday,asevidenceshowssittingforlongperiodsoftimecanincreaseyourriskofchronicdiseasessuchascancer,diabetesandCVD.21
The difference between ‘moderate’ and ‘vigorous-intensity’ physical activity
Thetalktestisaneasywaytodeterminewhetheryourphysicalactivitycanbeconsidered‘moderate’,or‘vigorous’.Ifyou’redoingmoderate-intensityactivityyoucantalk,butnotsing,duringtheactivity.Ifyou’redoingvigorous-intensityactivity,youwillnotbeabletosaymorethanafewwordswithoutpausingforabreath’.18
8
THE BENEFITS OF WALKING
Walkingisagreatwaytoincreasephysicalactivitylevels.Itisoneofthemostaccessibleformsofphysicalactivity:mostpeoplecandoit,itisfree,canbeeasilyincorporatedintoadailyroutine,andevidencehasshownthatitcanimproveyourhearthealth.22
Importantly,walkingbriskly(atapaceofatleast3mphor5kph)countstowardtheWHO’srecommendationthatadultsdoatleast150minutesaweekofmoderatephysicalactivity.
TheimpactofwalkingonreducingtheriskofCVD(includingheartdiseaseandstroke)hasbeenexaminedinseveralstudies,whichhavedemonstratedthatwalkingcan:
• reducetheriskofCVDbyover10%23
• decreasebodyweight,bodymassindex(BMI),bodyfatpercentageandwaistcircumference
• lowerbloodpressure,andincreaseaerobiccapacity(thecapacityofanindividual’sbodytotransportanduseoxygenduringexercise)byuptoaboutafifth
• lowerlevelsofthefatthatcancausehardeningandnarrowingofthearteries(triglycerides)24
• increase‘good’(HDL)cholesterol.25
OnestudyshowedthatwalkingatleasttwohoursaweekreducedtheincidenceofprematuredeathfromCVDbyabout50%.26
InadditiontoloweringtheriskofCVD,walkinghasbeenshowntoprovideotherhealthbenefits,including:
• reducingtheriskofothernon-communicablediseases,suchastype2diabetes,27andhavebenefitsforpeoplerecoveringfromcancer28
• improvesleeppatterns,boostenergylevels29
• increasemuscleendurance30
• mentalhealthbenefitsthroughthereleaseofhormones(chemicalsproducednaturallybyyourbody)calledendorphinsthatimprovemood-buildingself-esteemaswellasreducingfeelingsofstressandanxiety31
• decreasetheriskofdementia32
• reduceandalleviatejointandbackpainbyincreasingmusclestrengthandhelpingtokeepbonesstrong(whichmayalsohelpprotectagainstosteoporosis)33
• peoplewithchronicobstructivepulmonarydisease(COPD),whoundertakemorewalking,halvetheirriskofbeingadmittedasanemergencyadmission.34
Arecentstudyof400,000peoplefoundthat,just15minutesadayofbriskwalkingcanhavesignificanthealthbenefits,addinguptothreeyearstolifeexpectancy-andeveryadditional15minutesofdailyexercisereducedall-causedeathratesbyafurther4%.35
10
THE NEED FOR COLLABORATIVE ACTION
Heartdiseaseisoneofthemostcriticalhealthcarechallengesofourtime.However,thereisahugeopportunitytomakeadramaticdifferencetolivesofmillionsofpeople.Together,BupaandtheWorldHeartFederationarecommittedtohelpingpeoplereducetheirriskofCVD,bymotivatingandencouragingpeopletobemorephysicallyactive-bywalkingmore.
Alongwiththeheartspecific,andwiderhealthbenefitsofwalking,studieshavealsoshownthatwalkinghashigherlevelsof‘stickability’thanotherformsofphysicalactivity36-itisconvenientandovercomesmanyofthecommonlyperceivedbarrierstophysicalactivity:lackoftime,lackoffitnessorlackofskill.
Walking rates have
declined steadily over
several decades
Unfortunately,however,walkingrateshavedeclinedsteadilyoverseveraldecades.37Theproportionofchildrenwalkingorcyclingtoschoolfellfrom48%to13%between1969and2009intheUS,andfrom62%to50%between1989and2004amongprimaryschoolchildrenintheUK38-thisdeclineiscontinuingaroundtheworld.Forexample,inIndiarisingcarownershipisdiscouragingwalkingand,inChina,reducedwalkinghascontributedtoanincreaseinobesitylevels.
Together,Bupa,aleadinginternationalhealthcaregroupthatexiststohelppeoplelivehealthier,happier,longerlives,andtheWorldHeartFederation,thegloballeaderinthefightagainstCVD,arecommittedtoreversingtheincreasingprevalenceofCVD,aswellasthesedecliningwalkingrates.Inordertodoso,weallneedtoworktogethertosupportandmotivatepeopletogetwalkingandstaywalking.
11
TheWorldHeartFederationisdedicatedtoleadingtheglobalfightagainstCVDviaaunitedcommunityofmorethan200memberorganisations.
Withitsmembers,theWorldHeartFederationworkstobuildglobalcommitmenttoaddresscardiovascularhealthatthepolicylevel;generatesandexchangesideas;sharesbestpractice;advancesscientificknowledge;andpromotesknowledgetransfertotackleCVD-thenumberonekillerworldwide.
TheWorldHeartFederationisagrowingmembershiporganisationthatbringstogetherthestrengthofcardiacsocietiesandheartfoundationsfrommorethan100countries.
AlongsidetheWorldHealthOrganization,theWorldHeartFederationiscommittedtodrivinga25%reductioninprematuredeathsfromCVDby2025.
Formoreinformationvisit:www.world-heart-federation.org
ABOUT WORLD HEART FEDERATION
12
17.3 millionpeople around the world died from CVD in 2008
60%of people around the world are not doing enough physical activity
in 2008
30%of all deaths were due to CVD
23.3 millionpeople are expected to die from CVD (mainly from heart attack and stroke) by 2030
80%of all heart disease and stroke would be prevented if the major risk factors were eliminated - if we stopped smoking, ate a healthy diet and did enough physical activity.
13
Bupa’spurposeislonger,healthier,happierlives.
Aleadinginternationalhealthcaregroup,weserveover14millioncustomersinmorethan190countries.Weofferpersonalandcompany-financedhealthinsuranceandmedicalsubscriptionproducts,runhospitals,provideworkplacehealthservices,homehealthcare,healthassessmentsandchronicdiseasemanagementservices.Wearealsoamajorinternationalproviderofnursingandresidentialcareforelderlypeople.
Withnoshareholders,weinvestourprofitstoprovidemoreandbetterhealthcareandfulfilourpurpose.
Bupaemploysmorethan62,000people,principallyintheUK,Australia,Spain,Poland,NewZealandandtheUSA,aswellasSaudiArabia,HongKong,India,Thailand,ChinaandacrossLatinAmerica.
Formoreinformationvisit:www.bupa.com
ABOUT BUPA
14
1Globalstatusreportonnoncommunicable
diseases2010.Geneva,WorldHealthOrganization,
2011(accessedviahttp://www.who.int/
mediacentre/factsheets/fs317/en/index.html).
2Globalstatusreportonnoncommunicable
disaeses2010.Geneva,WorldHealthOrganization,
2011.
3Globalatlasoncardiovasculardiseaseprevention
andcontrol.Geneva,WorldHealthOrganization,
2011.
4Globalstatusreportonnoncommunicable
diseases2010.Geneva,WorldHealthOrganization,
2011.
5Cardiovasculardiseases(CVDs)FactsheetN°317,
WorldHealthOrganisation,2013http://www.who.
int/mediacentre/factsheets/fs317/en/.
6Preventingchronicdiseases:avitalinvestment:
WHOglobalreport,2005:http://whqlibdoc.who.
int/publications/2005/9241563001_eng.pdf.
7PhysicalInactivity,WorldHeartFederationhttp://
www.world-heart-federation.org/cardiovascular-
health/cardiovascular-disease-risk-factors/
physical-inactivity/.
8Cardiovasculardiseases(CVDs)FactsheetN°317,
WorldHealthOrganisation,2013http://www.who.
int/mediacentre/factsheets/fs317/en/.
9PhysicalActivity,WorldHealthOrganisation
http://www.who.int/dietphysicalactivity/pa/en/.
10CardiovascularDisease:ControllingHighBlood
Pressure,WorldHealthOrganisationhttp://www.
who.int/cardiovascular_diseases/en/.
11http://whqlibdoc.who.int/
publications/2010/9789241599979_eng.pdf.
12RiskFactor:PhysicalInactivity,WorldHealth
Organisationhttp://www.who.int/cardiovascular_
diseases/en/cvd_atlas_08_physical_inactivity.pdf.
13http://www.who.int/dietphysicalactivity/
factsheet_inactivity/en/index.html.
14http://www.who.int/dietphysicalactivity/
factsheet_inactivity/en/index.html.
15http://www.who.int/dietphysicalactivity/
factsheet_inactivity/en/index.html.
16ReftoL.Farrelletal.,TheSocioeconomic
GradientinPhysicalInactivityinEngland,Working
Paper13/311,UniversityofBristol:http://www.bris.
ac.uk/cmpo/publications/papers/2013/wp311.pdf.
17Source:Globalrecommendationson
physicalactivityforhealth,WorldHealth
Organization2010.http://whqlibdoc.who.int/
publications/2010/9789241599979_eng.pdf.
18USCentersforDiseaseControlandPrevention
http://www.cdc.gov/physicalactivity/everyone/
measuring/index.html.
1910FactsonPhysicalActivity,WorldHealth
Federationhttp://www.who.int/features/factfiles/
physical_activity/facts/en/index8.html.
20LoprinziPDandCardinalBJ‘Association
betweenbiologicoutcomesandobjectively
measuredphysicalactivityaccumulatedin
>10-minuteboutsand<10-minutebouts’,
AmericanJournalofHealthPromotion(2013)
http://www.ncbi.nlm.nih.gov/pubmed/23286590.
21EmmaSGeorge,RichardRRosenkranzand
GregorySKolt,‘Chronicdiseaseandsittingtime
inmiddle-agedAustralianmales:findingsfrom
the45andUpStudy’,InternationalJournalof
BehavioralNutritionandPhysicalActivity2013
10:20:http://www.ijbnpa.org/content/10/1/20.
22GetWalking,KeepWalking,BupaandC3
CollaboratingforHealthhttp://www.bupa.com/
media/478232/get_walking_final_22_06_12.pdf.
23Citedinmurtagh,e.m.,m.h.murphyandJ.
boone-heinonen,‘walking-thefirststepsto
cardiovasculardiseaseprevention’,CurrOpin
Cardio.(2010)25(5):490-6:http://www.ncbi.nlm.
nih.gov/pubmed/20625280.
24Gordon-Larsen,p.,etal.,‘activecommutingand
cardiovasculardiseaserisk:theCardiastudy.’arch
internmed.(2009)169:1216-23:http://www.ncbi.
nlm.nih.gov/pubmed/19597071.
REFERENCES
15
25Parkkari,J.,A.Natri,P.Kannus,A.Mänttäri,R.
Laukkanen,H.Haapasalo,etal.,‘Acontrolledtrial
ofthehealthbenefitsofregularwalkingonagolf
course’,AmericanJournalofMedicine(2000)
109:102-8.http://www.amjmed.com/article/
S0002‐9343(00)00455‐1/abstract.
26PhysicalInactivity,WorldHeartFederation
http://www.world-heart-federation.org/
cardiovascular-health/cardiovascular-disease-risk-
factors/physical-inactivity/.
27Review:Thebenefitsofphysicalactivityfor
healthandwell-being,C3Collaboratingfor
Healthhttp://www.c3health.org/wp-content/
uploads/2009/09/C3-review-of-physical-activity-
and-health-v-1-20110603.pdf.
28MacmillanCancerSupport,‘Theimportanceof
physicalactivityforpeoplelivingwithandbeyond
cancer:aconciseevidencereview’(2012):http://
www.macmillan.org.uk/Documents/AboutUs/
Commissioners/Physicalactivityevidencereview.
pdf.
29Review:Thebenefitsofphysicalactivityfor
healthandwell-being,C3Collaboratingfor
Healthhttp://www.c3health.org/wp-content/
uploads/2009/09/C3-review-of-physical-activity-
and-health-v-1-20110603.pdf.
30Parkkari,J.,A.Natri,P.Kannus,A.Mänttäri,R.
Laukkanen,H.Haapasalo,etal.,‘Acontrolledtrial
ofthehealthbenefitsofregularwalkingonagolf
course’,AmericanJournalofMedicine(2000)
109:102-8.http://www.amjmed.com/article/
S0002‐9343(00)00455‐1/abstract.
31Walkingandhealth,Bupahttp://www.bupa.
co.uk/individuals/health-information/directory/w/
walking-health.
32JEAhslkogetal.,‘Physicalexerciseasa
preventiveordisease-modifyingtreatmentof
dementiaandbrainaging’,MayoClinProc(2011)
86(9)876-885:http://www.ncbi.nlm.nih.gov/
pubmed/21878600.
33Walkingandhealth,Bupahttp://www.bupa.
co.uk/individuals/health-information/directory/w/
walking-health.
34Garcia-Aymerich,J.etal.,‘Riskfactorsof
readmissiontohospitalforaCOPDexacerbation:
aprospectivestudy’,Thorax(2003)58(2):100-5:
http://www.ncbi.nlm.nih.gov/pubmed/12554887,
citedinCavill,N.andC.Foster,HealthBenefits
ofWalking:TheEvidenceBase(2008):http://
nationalcampaignforwalking.net/evidence/.
35Wen,C.P.etal.,‘Minimumamountofphysical
activityforreducedmortalityandextended
lifeexpectancy:aprospectivecohortstudy’,
TheLancet(2011)378:9798:1244-53:http://
www.thelancet.com/journals/lancet/article/
PIIS0140‐6736%2811%2960749‐6/abstract.
36Lamb,S.E.,H.P.Bartlett,A.AshleyandW.Bird,
‘Canlay-ledwalkingprogrammesincreasephysical
activityinmiddleagedadults?arandomised
controlledtrial’,JournalofEpidemiologyand
CommunityHealth(2002)56:246-25:http://jech.
bmj.com/content/56/4/246.abstract;J.Parkkari,
etal.,‘acontrolledtrialofthehealthbenefits
ofregularwalkingonagolfcourse’,American
JournalofMedicine(2000)109:102-8:http://
www.ncbi.nlm.nih.gov/pubmed/10967150;Zunft,
H.F.,etal.,‘perceivedbenefitsandbarriersto
physicalactivityinanationallyrepresentative
sampleintheeuropeanunion’,PublicHealth
Nutrition(1999)2:153-60:http://journals.
cambridge.org/action/displayabstract?frompage=
online&aid=554588.
37Hu,P.andT.Reuscher,SummaryofTravel
Trends(2004,Washington,DC:U.S.Department
ofTransportation):http://nhts.ornl.gov/2001/pub/
stt.pdf.
38 NationalCenterforSafeRoutestoSchool,
HowChildrengettoSchool:SchoolTravel
Patternsfrom1969to2009(2011):http://
www.saferoutesinfo.org/sites/default/files/
resources/NHTS_school_travel_report_2011_0.
pdf,p.2.Killoran,A.,etal.,TransportInterventions
promotingSafeCyclingandWalking:Evidence
Briefing(2006):https://nice.org.uk/nicemedia/
pdf/Transport_Evidence_Briefing_05-07.
pdf,Table1,p.10.