Racial/Ethnic- and Education-Related Disparities in the Control of Risk Factors for Cardiovascular Disease Among Individuals With Diabetes.

0.14 MB·English

by  Chatterji, Pinka

Epidemiology/Health Services Research
O R I G I N A L A R T I C L E
Racial/Ethnic- and Education-Related
Disparities in the Control of Risk Factors
for Cardiovascular Disease Among
Individuals With Diabetes
PINKA CHATTERJI, PHD toexperienceaCVDevent(4),andindivid-
HEESOO JOO, BBA, BS ualswithdiabeteshaveheartdiseasemor-
KAJAL LAHIRI, PHD talityratesthataretwotofourtimesgreater
thanthosewithoutdiabetes(6).
TopreventCVDandothercomplica-
OBJECTIVEdThereislimitedinformationonwhetherrecentimprovementsinthecontrolof tions of diabetes, the American Diabetes
cardiovasculardisease(CVD)riskfactorsamongindividualswithdiabeteshavebeenconcen-
Association (ADA) in 2009 published
tratedinparticularsociodemographicgroups.Thisarticleestimatesracial/ethnic-andeducation-
updatedstandardsfordiabetesscreening,
related disparities and examines trends in uncontrolled CVD risk factors among adults with
diagnosis,andtherapeuticcare(7).These
diabetes. The main racial/ethnic comparisons made are with African Americans versus non-
guidelines, which reflect new evidence
LatinowhitesandMexicanAmericansversusnon-Latinowhites.
from epidemiological studies and random-
RESEARCHDESIGNANDMETHODSdTheanalysissamplesincludeadultsaged$20 izedcontrolledtrials,includedtargetsforgly-
yearsfromtheNationalHealthandNutritionExaminationSurvey(NHANES)1988–1994and cemiccontrol,bloodpressurecontrol,lipid
theNHANES1999–2008whoself-reportedhavingdiabetes(n=1,065,NHANES1988–1994;
control,andsmoking(7).TheADArecom-
n=1,872,NHANES1999–2008).Byuseoflogisticregressionmodels,weexaminedthecorre-
mendsthatmostadultswithdiabetesmain-
lates of binary indicators measuring 1) high blood glucose, 2) high blood pressure, 3) high
tainanHbA (ameasureofbloodglucose)
cholesterol,and4)smoking. 1c
levelbeloworaround7.0%,bloodpressure
RESULTSdControlofbloodglucose,bloodpressure,andcholesterolimprovedamongindi- under130/80mmHg,andLDLcholesterol
vidualswithdiabetesbetweentheNHANES1988–1994andtheNHANES1999–2008,butthere under100mg/dL(2.6mmol/L)(7).Allpa-
wasnochangeinsmokingprevalence.IntheNHANES1999–2008,racial/ethnicminoritiesand tientswithdiabetesareadvisednottosmoke.
individualswithoutsomecollegeeducationweremorelikelytohavepoorlycontrolledblood Inaddition,theNationalCholesterolEduca-
glucosecomparedwithnon-Latinowhitesandthosewithsomecollegeeducation.Inaddition,
tionProgramAdultTreatmentPanelIIIrec-
individualswithdiabeteswhohadatleastsomecollegeeducationwerelesslikelytosmokeand
ommends that individuals with diabetes
hadbetterbloodpressurecontrolcomparedwithindividualswithdiabeteswithoutatleastsome
keeptheirLDLunder100mg/dLandtotal
collegeeducation.
cholesterolunder200mg/dL(8).
CONCLUSIONSdTrends in CVD risk factors among individuals with diabetes improved Giventhatsuccessfulmanagementof
over the past 2 decades, but racial/ethnic- and education-related disparities have emerged in diabetes requires a coordinated team of
someareas. health care providers (7) and access to
health insurance (9), continuity of care
DiabetesCare35:305–312,2012
(10), and patient knowledge and self-
D managementskills(11),theremaybedif-
iabetesisaleadingcauseofmorbidity ~33%($58billion)ofthetotalcostbeing ferences in control of CVD risk factors
and mortality in the U.S., and the attributed to treatment of medical com- across sociodemographic groups within
prevalence of this disease is rising plications (3). Cardiovascular disease the population of people with diabetes.
(1).TheCentersforDiseaseControland (CVD) is a widely documented potential On the basis of data from the National
Prevention,basedondatafromtheNational complication of diabetes and a leading HealthandNutritionExaminationSurvey
HealthInterviewSurvey,estimatedthatthe cause of mortality among individuals (NHANES)1999–2000,previousresearch-
age-adjustedprevalenceofdiagnoseddiabe- with diabetes (4–6). Although rates of ers reported that only 7.3% of those with
tesincreasedfrom3.7%in1980to7.7%in CVD events have declined in recent de- diagnosed diabetes achieve all three of the
2008(2).Thetotaldirectandindirectcosts cades among both individuals with and ADA(2009)targetsforcontrolofbloodglu-
associatedwithdiabetesintheU.S.were withoutdiabetes,peoplewithdiabetesstill cose, blood pressure, and total cholesterol
estimatedtobe$174billionin2007,with aretwiceaslikelyasthosewithoutdiabetes (12). Between the NHANES 1988–1994
and the NHANES 1999–2000, trends in
c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c
thecontrolofbloodcholesterolamongin-
FromtheDepartmentofEconomics,UniversityatAlbany,StateUniversityofNewYork,Albany,NewYork.
dividuals with diagnosed diabetes im-
Correspondingauthor:PinkaChatterji,[email protected].
Received26July2011andaccepted31October2011. proved, but there was no change in the
DOI:10.2337/dc11-1405 controlofbloodglucoseandbloodpressure
Theopinionsexpressedinthisarticlearethoseoftheauthorsanddonotnecessarilyreflecttheviewsofthe levels(12).Poorglycemiccontrolgenerally
NationalInstituteonMinorityHealthandHealthDisparitiesortheNationalInstitutesofHealth.
ismoreprevalentamongAfricanAmericans
©2012bytheAmericanDiabetesAssociation.Readersmayusethisarticleaslongastheworkisproperly
cited,theuseiseducationalandnotforprofit,andtheworkisnotaltered.Seehttp://creativecommons.org/ andMexicanAmericanswithdiabetescom-
licenses/by-nc-nd/3.0/fordetails. paredwithnon-Latinowhiteswithdiabetes
care.diabetesjournals.org DIABETESCARE,VOLUME35,FEBRUARY2012 305
DisparitiesinCVDriskfactorsindiabeticindividuals
(13–15), but these differences have been information are available only for those diagnosed diabetes. When we estimated
small in some studies (13) and limited to NHANES respondents who participated the prevalence rates of diagnosed diabetes,
certain sex/race-ethnicity subgroups in inthemedicalexaminationportionofthe weusedallrespondentsfromtheNHANES
other studies (14). Recent research based survey, which included a blood draw. 1988–1994 and the NHANES 1999–2008
onindividualswithdiabetesinterviewedin Smoking information was obtained from samples who provided a response to this
theNHANES1999–2008showsanoverall theinterview. question.
trend of improvement in CVD risk factors Thesesamplerestrictionsyielded1,149 Todefinepoorcontrolofbloodglucose
and, notably, reductions in the predicted respondents in the NHANES 1988–1994 andbloodpressure,wefollowedtheADA
10-yearriskofcoronaryheartdisease(16), sample and 2,056 respondents in the 2009guidelines.Wedefinedpoorglycemic
butsomefindingsshowthatsocioeconomic NHANES 1999–2008 sample. After ex- controlusingabinaryindicatorofhavingan
status and racial/ethnic disparities persist cludingrespondentswithmissingsociode- HbA $7%. To define poor blood pres-
1c
(14–18). mographic characteristics used in the surecontrol,weusedabinaryindicatorof
UsingdatafromtheNHANES1988– analysis,ourfinalanalysissamplesincluded having a systolic blood pressure $130
1994 and the NHANES 1999–2008, we 1,065 respondents from the NHANES mmHg or diastolic blood pressure $80
builtontheseimportantnewresultsby1) 1988–1994 and 1,872 respondents from mmHg.TheNHANES1988–1994medical
examiningtrendsintheprevalenceofdi- the NHANES 1999–2008. The main examinationincludedthreereadingsofsys-
agnosed diabetes and the sociodemo- racial/ethnic comparisons made were tolicanddiastolicbloodpressure.Forthis
graphic characteristics of the diagnosed between African Americans versus non- sample,weusedtheaverageofthesecond
diabetic population and 2) testing for Latino whites and Mexican-Americans andthirdreadings.IntheNHANES1999–
racial/ethnic- and education-related dis- versus non-Latino whites. Latinos from 2008,threeorfourbloodpressurereadings
parities in poorly controlled risk factors countriesoforiginotherthanMexicoare were available for each respondent. Thus,
for CVD among individuals with diag- included in the “other” race/ethnicity forthissample,weusedtheaverageofthe
noseddiabetes.Giventhemountingbody category. secondandthirdreadingswhentheywere
of evidence showing the importance of Theage-andsex-adjustedproportion bothavailable,andweusedtheaverageof
controlling CVD risk factors (7) and the ofrespondentswithnonmissinginforma- thethirdandfourthmeasureortheaverage
increasing focus on prevention in the tion on control of CVD risk factors de- ofthesecondandfourthmeasureofblood
2010 health care reform law (19), it is creased from 93.7% in the NHANES pressurein193casesubjectsforwhomthe
critical to document current trends in 1988–1994 to 81.1% in the NHANES secondorthirdmeasureofbloodpressure
the control of CVD risk factors among 1999–2008. We tested for differences in wasmissingandafourthmeasurewasavail-
individualswithdiabetesandtoexamine observedcharacteristicsbetweenthosein- able.Wedefinedadichotomousindicator
whether any improvements have been cluded in the sample and those excluded of current smoking, which equaled 1 if a
concentrated in particular sociodemo- fromthesamplebecauseofmissingdata.In respondentreported“yes”tothequestion,
graphicgroups. both the NHANES 1988–1994 and the “Haveyousmokedatleast100cigarettesin
NHANES 1999–2008, minority individu- yourentirelife?”anddidnotanswer“notat
RESEARCH DESIGN AND als were overrepresented among missing all” to the question, “Do you now smoke
METHODS cases.Inaddition,intheNHANES1999– cigarettes...”intheNHANES1999–2008.
2008, those with less than a high-school IntheNHANES1988–1994,wedefineda
Study population and analysis education were overrepresented among current smoker as someone who reported
samples missingcases.Whenweranaprobitregres- “yes”toboth“Haveyousmokedatleast100
We used two samples, a sample from the sionmodelwith“missingfromsample”as cigarettesduringyourentirelife?”and“Do
NHANES 1988–1994 and a sample from the dependent variable, we found that in yousmokecigarettesnow?”
the NHANES 1999–2008. The NHANES boththeNHANES1988–1994andinthe To measure lipid control, we used the
used a stratified, multistage probability- NHANES1999–2008,theonlystatistically total cholesterol level, which follows the
samplingframeandrepresentedthecivilian, significantpredictorofbeingmissingfrom AdultTreatmentPanelIIIguidelines,instead
noninstitutionalized U.S. population. The thesamplewasAfricanAmericanrace.We ofLDLcholesterol,assuggestedbytheADA
NHANES 1988–1994 interviewed 18,825 emphasize, however, that there is nosta- in 2009, because of the small sample sizes
individuals aged $20 years. We limited tistically significant difference in the esti- with available LDL cholesterol information
ourNHANES1988–1994sampleto1,503 matedcoefficientonAfricanAmericanrace intheNHANES(n=335intheNHANES
of these respondents who reported having in the NHANES 1988–1994 versus the 1988–1994,n=785intheNHANES1999–
been diagnosed with diabetes. In the NHANES1999–2008,suggestingthatthe 2008).Thesmallsamplesizesresultedfrom
NHANES 1999–2008, 26,246 individuals possiblebiasresultingfromexcludingob- theLDLcholesterolmeasurementonlybe-
aged $20 years were interviewed, and we servations with incomplete information is ingavailableforthosewhowereassigneda
limitedourNHANES1999–2008sampleto likelytobeminimal. NHANES medical examination scheduled
2,802 of these respondents who reported inthemorning.Weusedabinaryindicator
having been diagnosed with diabetes. Definitions and measures for total cholesterol of $200 mg/dL as an
Amongthosewhoreportedhavingdiabetes, We considered an individual to have di- indicatorforpoorlipidcontrol.
we further limited NHANES 1988–1994 agnoseddiabetesifheorsheanswered“yes”
andNHANES1999–2008samplestothose to the interview question, “Have you ever Analyses
who had information regarding all four beentoldbyadoctororhealthprofessional Initially,weexaminedtrendsintheprev-
CVD risk factors (blood glucose, blood that you have diabetes or sugar diabetes?” alence of diagnosed diabetes and the
pressure, lipids, and current smoking). We did not consider respondents who re- sociodemographiccharacteristicsofthedi-
Blood glucose, blood pressure, and lipid ported having gestational diabetes to have agnosed diabetic populations in the
306 DIABETESCARE,VOLUME35,FEBRUARY2012 care.diabetesjournals.org
Chatterji,Joo,andLahiri
NHANES 1988–1994 and the NHANES between the NHANES 1988–1994 and usingStatasoftware,version11.1(StataCorp,
1999–2008 samples. We reported age- theNHANES1999–2008(Table3)(20). CollegeStation,TX).
andsex-adjustedaswellasunadjustedprev- Weusedlogisticmodelsestimatedwith
alenceratesofdiagnoseddiabetes(Table1). surveyweightstotestforracial/ethnic-and RESULTS
Standardizationwasbasedonthe2000U.S. education-relateddisparitiesinpoorlycon-
Census population, using sex and age trolledriskfactorsforCVDamongindivid- Trends in diagnosed diabetes and
(5-year agecategoriesforthoseaged20– ualswithdiagnoseddiabetes(Table4).The characteristics of the population
79 years and a category for those aged modelsincludedcontrolsforrace/ethnicity with diagnosed diabetes
$80 years). We then examined sample (African American, Mexican American, Asothershavereported(2,21),theprev-
characteristics of the population with other race/ethnicity versus non-Latino alence of diagnosed diabetes has in-
diagnosed diabetes in the NHANES whites), age categories (5-year age catego- creased appreciably over time (Table 1).
1988–1994andtheNHANES1999–2008 riesforthoseaged20–79yearsandacate- The age- and sex-standardized preva-
(Table 2) and, in Table 3, estimated the goryforthoseaged$80years),sex(female lence rate of diagnosed diabetes in the
rates of poor control of CVD risk factors vs. male), marital status (married vs. not NHANES1999–2008was7.4%,whereas
in the NHANES 1988–1994 and the married), years since diagnosis of diabetes it was 5.3% in the NHANES 1988–1994
NHANES 1999–2008 samples and by (2–5,6–10,11–15,and$16yearsvs.0–1 (P , 0.001). The unadjusted prevalence
racial/ethnic and education groups. In years), obesity (BMI 25–29 kg/m2 [over- ofdiagnoseddiabetesshowsthesamepat-
Tables 2–3, the NHANES 1988–1994 weight], BMI $30 kg/m2 [obese] vs. BMI tern, increasing from 5.1% in the
percentageswerestandardizedaccording ,25 kg/m2 [normal]), access to routine NHANES 1988–1994 to 7.5% in the
to the NHANES 1999–2008 population care (has routine access vs. does not have NHANES1999–2008(P,0.001),which
of individuals with diagnosed diabetes, routineaccess),healthinsurancetype(pub- isconsistentwithpreviousresearch(22).
using age-sex groups and their corre- lic,publicandprivate,oruninsuredvs.pri- Between the NHANES 1988–1994 and
spondingweights(12).Wecomparedthe vate only), and indicators for survey year. the NHANES 1999–2008, the incidence
rates of poor control of CVD risk factors All analyses in this article were performed of diabetes (diagnosed and undiagnosed)
increased from 7.9 to 10.1% (results not
shown).Wefoundthatamongthosewith
Table1dPrevalenceratesof diagnoseddiabetesamongadultsaged ‡20years diabetes (diagnosed and undiagnosed),
therateofundiagnoseddiabetesdecreased
NHANES NHANES P(NHANES1988–1994vs.NHANES from 38.2 to 28.4% (results not shown),
1988–1994 1999–2008 1999–2008) suggesting that diagnosis has improved
overtime.
n 16,552 24,674 d Oneofthemostsignificantchangesin
Unadjusteddiagnosed
thecharacteristicsofthepopulationwith
diabetes 5.1(0.26) 7.5(0.26) ,0.001
diagnoseddiabetesbetweentheNHANES
Race 1988–1994 and the NHANES 1999–
Non-Latinowhite 4.9(0.35) 6.7(0.32) ,0.001
2008 is the race/ethnicity distribution.
AfricanAmerican 6.9(0.43)* 11.5(0.49)* ,0.001
Table2shows theincreases overtime in
MexicanAmerican 5.5(0.32) 7.3(0.37) ,0.001
the proportions of Mexican Americans
Education
(from5.9to8.0%,P=0.10)andindivid-
Lessthanhigh ualsfromthe“other”race/ethnicitygroup
Ć school 8.5(0.49) 12.1(0.44) ,0.001
(from 6.0 to 12.2%, P = 0.002) in the
High-school
population with diagnosed diabetes,
Ć graduate 4.8(0.43)* 7.6(0.44)* ,0.001
whereas the proportion of non-Latino
Morethanhigh
whites declined (from 73.6 to 65.3%,
Ć school 3.2(0.35)* 5.8(0.31)* ,0.001
P=0.009).ForAfricanAmericans,there
Standardizeddiagnosed is no statistically significant change be-
diabetes 5.3(0.23) 7.4(0.25) ,0.001 tween the NHANES 1988–1994 and the
Race NHANES1999–2008(Table2).
Non-Latinowhite 4.9(0.30) 6.1(0.29) 0.004
Theagedistributionofthepopulation
AfricanAmerican 8.4(0.44)* 12.6(0.44)* ,0.001
with diagnosed diabetes also changed be-
MexicanAmerican 9.8(0.51)* 11.6(0.45)* 0.008 tween the NHANES 1988–1994 and the
Education NHANES 1999–2008 (Table 2). The pro-
Lessthanhigh
portion of middle-aged individuals in-
Ć school 7.4(0.45) 10.7(0.38) ,0.001 creasedovertime(aged40–59years,from
High-school
34.5to41.6%,P=0.01),whereasthepro-
Ć graduate 5.4(0.42)* 7.2(0.41)* 0.002
portion of elderly individuals declined
Morethanhigh (aged$60years,from55.6to49.5%,P=
Ć school 3.9(0.32)* 6.0(0.32)* ,0.001
0.03).Thistrendmayhaveresultedfroman
Dataare%(SE).Theage-andsex-adjustedratesfordiagnoseddiabetesareadjustedusingdatafromthe2000 earlierdiagnosisofdiabetesand/oranearlier
U.S.Census.ThePvaluesarederivedfromtteststhatdeterminewhethertheratesdifferbetweenNHANES
onset of diabetes in recent years. In fact,
1988–1994andNHANES1999–2008.The“other”race/ethniccategoryisnotshown.*Thedifferencebe-
wefound that mean ageatthe time of di-
tweenthereferencegroup(non-Latinowhiteforraceandlessthanhighschoolforeducation)andeachraceor
educationgroupwithinthesameperiodisstatisticallysignificantwithP,0.05. abetesdiagnosisishigherintheNHANES
care.diabetesjournals.org DIABETESCARE,VOLUME35,FEBRUARY2012 307
DisparitiesinCVDriskfactorsindiabeticindividuals
Table2dSamplecharacteristics ofadultswithdiagnoseddiabetes Trends in poor control of CVD
risk factors
NHANES NHANES P(NHANES1988–1994vs. OurfindingssuggestthatcontrolofCVD
1988–1994 1999–2008 NHANES1999–2008) risk factors among individuals with di-
agnoseddiabeteshasimprovedmarkedly
N 1,065 1,872 overthepasttwodecades(Table3).The
Race percentage of those with diagnosed dia-
Non-Latinowhite 73.6(2.08) 65.3(2.35) 0.009 betes not achieving glycemic control
AfricanAmerican 14.6(1.46) 14.6(1.38) 0.99 (HbA .7%)was50.0%intheNHANES
1c
MexicanAmerican 5.9(0.73) 8.0(1.04) 0.10 1999–2008, an improvement from the
Otherrace/ethnicity 6.0(1.23) 12.2(1.56) 0.002 NHANES 1988–1994, when 57.7% of
Sex(female) 54.1(2.48) 50.7(1.58) 0.25 people with diagnosed diabetes did not
Age(years) meetthistarget(P=0.008).Thepercent-
20–39 9.9(2.08) 8.9(0.92) 0.65 age of individuals with diagnosed diabe-
40–59 34.5(2.21) 41.6(1.43) 0.01 tes who do not achieve blood pressure
$60 55.6(2.42) 49.5(1.47) 0.03 control ($130/80 mmHg) decreased
Married 65.5(1.90) 60.8(1.44) 0.05 from60.8%intheNHANES1988–1994
Education to 53.5% in the NHANES 1999–2008
Lessthanhighschool 41.9(2.94) 29.9(1.22) ,0.001 (P = 0.01). The percentage of people
High-schoolgraduate 30.9(2.08) 25.8(1.37) 0.04 with diagnosed diabetes who did not
Morethanhighschool 27.1(2.80) 44.4(1.56) ,0.001 have total cholesterol ,200 mg/dL also
Yearssincediabeteswas significantly fell from 67.1% in the
diagnosed NHANES 1988–1994 to 41.3% in the
0–1 17.6(1.58) 14.3(1.17) 0.10 NHANES 1999–2008. Rates of current
2–5 29.6(1.90) 26.6(1.38) 0.20 smoking among individuals with diag-
6–10 18.5(1.23) 21.7(1.23) 0.07 noseddiabetes,however,didnotchange
11–15 15.3(1.82) 14.5(1.06) 0.70 between the NHANES 1988–1994
$16 19.0(1.86) 22.9(1.19) 0.08 (17.5%) and the NHANES 1999–2008
BMI(kg/m2) (18.1%,P=0.81).
25–29(overweight) 38.1(2.40) 29.4(1.44) 0.002 Ofnote,ouranalysesshowatrendof
$30(obese) 43.2(2.60) 54.8(1.66) ,0.001 improvement not only in the control of
Routineplaceformedical eachriskfactorindividuallybutalsointhe
care 96.4(0.81) 97.8(0.35) 0.11 number of controlled risk factors. In the
Privateinsuranceonly 41.2(2.13) 40.3(1.41) 0.70 NHANES1988–1994,only5.2%ofthose
Publicinsuranceonly 19.7(1.87) 27.1(1.26) 0.001 withdiagnoseddiabeteshadcontrolofall
Privateandpublic ofthefourriskfactorsweexamined.Inthe
insurance 31.3(1.52) 20.9(1.06) ,0.001 NHANES1999–2008,however,13.6%of
Noinsurance 7.8(1.11) 11.7(0.96) 0.009 individuals with diagnosed diabetes had
Dataare%(SE).SamplestatisticsintheNHANES1988–1994arestandardizedbyage-sexadjustingtothe controlofallfourriskfactors(P,0.001)
NHANES 1999–2008 diagnosed diabetes sample. The P values are derived from t tests that determine (results not shown). In addition, the per-
whethertheratesdifferbetweentheNHANES1988–1994andtheNHANES1999–2008.Thistablepresents centageofpeoplewithdiagnoseddiabetes
broadagecategories,butintheregressionanalysesandintheage/sexstandardizationoffiguresweused whohadcontrolofthreeoffourriskfactors
5-yearageintervalsuptoage79years.
increasedfrom24.1to31.0%(P=0.003)
betweentheNHANES1988–1994andthe
1988–1994 than in the NHANES 1999– increasinglevelofeducationinthepop- NHANES1999–2008.Nevertheless,inthe
2008 (aged 49.3 vs. 46.8 years, P , ulationasawhole.BetweentheNHANES NHANES1999–2008,morethanone-half
0.001), and the number of years since 1988–1994andtheNHANES1999–2008, ofthepopulationwithdiagnoseddiabetes
diabeteswasdiagnosedwas9.1yearsin the age- and sex-standardized percentage (54.4%) still had more than two uncon-
the NHANES 1988–1994 versus 11.4 ofNHANES respondents aged$20 years trolledriskfactors(resultsnotshown).
years in the NHANES 1999–2008 (P , withatleastsomepostsecondaryeducation
0.001). rose from 27.1% in the NHANES 1988– Racial/ethnic- and education-related
In addition, the education profile of 1994 to 44.4% in the NHANES 1999– disparities in poor control
individuals with diagnosed diabetes 2008(P,0.001).Finally,thepopulation of CVD risk factors
changedremarkablybetweentheNHANES with diagnosed diabetes has become In the NHANES 1988–1994, there were
1988–1994andtheNHANES1999–2008 moreobeseovertime,withobesitylevels nostatisticallysignificantracial/ethnicor
(Table 2). The proportion of high-school increasing from 43.2% in the NHANES education-related disparities in glycemic
dropoutsamongindividualswithdiagnosed 1988–1994 to 54.8% in the NHANES control among individuals with diag-
diabetes decreased from 41.9 to 29.9% 1999–2008 (P , 0.001). The percentage nosed diabetes, although some of the
(P=0.001),whereasthepercentagewith of people who were either obese or over- CIswerewide(Table4,Bloodglucosecol-
some postsecondary education increased weightalsoincreasedbetweentheNHANES umn).IntheNHANES1999–2008,how-
from27.1to44.4%(P,0.001).Tosome 1988–1994 (81.3%) and the NHANES ever, we found that African Americans
extent, this change resulted from an 1999–2008(84.2%). and Mexican Americans with diagnosed
308 DIABETESCARE,VOLUME35,FEBRUARY2012 care.diabetesjournals.org
Chatterji,Joo,andLahiri
Table3dPoorcontrolofrisk factorsamongadultswithdiagnoseddiabetes quality-of-care mechanisms of disparities,
specifically whether the respondent had
NHANES NHANES P(NHANES1988–1994vs. seen a diabetes specialist in the past year,
1988–1994 1999–2008 NHANES1999–2008) whethertherespondentusuallysawapar-
ticulardoctorfordiabetes,andwhetherthe
Poorglycemiccontrol(HbA respondentcheckedhisorherownblood
1c
$7%) 57.7(2.27) 50.0(1.76) 0.008 glucoselevel.Theseadditionalvariablesare
Race available in the latest two waves of the
Non-Latinowhite 56.0(3.04) 46.7(2.42) 0.02 NHANES only. After these covariates
AfricanAmerican 62.3(3.05) 55.5(2.30)* 0.08 were included, both racial/ethnic-related
MexicanAmerican 63.3(2.46) 55.7(1.82)* 0.02 disparities and education-related dispari-
Education tieswerenotchangedappreciably,suggest-
Lessthanhighschool 55.1(2.67) 56.1(2.62) 0.79 ingthatthesemechanisms(iftheyindeed
High-schoolgraduate 62.5(3.62) 48.9(3.52) 0.008 werecapturingqualityofcare)didnotex-
Morethanhighschool 56.6(4.20) 45.4(2.42)* 0.02 plainthedisparitiesweobservedinrecent
Poorbloodpressurecontrol years.However,weinterpretedthesefind-
($130/80mmHg) 60.8(2.16) 53.5(1.79) 0.01 ings with caution because the additional
Race covariates included may have captured
Non-Latinowhite 60.3(2.94) 51.2(2.60) 0.02 theseverityofdiseaseinsteadoforinaddi-
AfricanAmerican 70.1(2.56)* 59.1(2.31)* 0.002 tion to quality of care. In that case, there
MexicanAmerican 59.6(2.42) 50.7(2.54) 0.01 mayhavebeenareverse-causalityproblem,
Education withpoorcontrolofdiabetesdrivingsever-
Lessthanhighschool 66.8(2.71) 58.0(2.43) 0.02 ityinsteadoftheotherwayaround.
High-schoolgraduate 60.1(3.24) 56.9(3.09) 0.48 We did not find racial/ethnic differ-
Morethanhighschool 56.5(3.51)* 47.2(2.78)* 0.04 ences in blood pressure control among
Poortotalcholesterolcontrol individuals with diagnosed diabetes in
($200mg/dL) 67.1(1.89) 41.3(1.54) ,0.001 either the NHANES 1988–1994 or the
Race NHANES 1999–2008 (Table 4, Blood
Non-Latinowhite 70.4(2.35) 40.9(2.23) ,0.001 pressure column). Individuals with diag-
AfricanAmerican 66.5(3.44) 40.6(2.17) ,0.001 nosed diabetes who had some postsec-
MexicanAmerican 60.9(3.54)* 44.8(2.23) ,0.001 ondary education were less likely than
Education those without postsecondary education
Lessthanhighschool 68.6(2.25) 44.4(2.61) ,0.001 to be in poor control of blood pressure,
High-schoolgraduate 62.3(2.92) 40.6(2.79) ,0.001 butthisassociationwasstatisticallysignif-
Morethanhighschool 76.3(2.50)* 40.3(2.40) ,0.001 icant only in the NHANES 1999–2008
Currentsmoking 17.5(2.20) 18.1(1.00) 0.81 data. There were no racial/ethnic dispar-
Race ities in total cholesterol control among
Non-Latinowhite 16.6(2.94) 18.1(1.58) 0.65 individuals with diagnosed diabetes in
AfricanAmerican 22.4(2.31) 21.8(2.30) 0.86 either the NHANES 1988–1994 or the
MexicanAmerican 19.4(2.38) 17.4(1.41) 0.47 NHANES1999–2008(Table4,Totalcho-
Education lesterolcolumn).Theassociationbetween
Lessthanhighschool 16.1(2.97) 22.2(2.07) 0.09 postsecondary education and control of
High-schoolgraduate 23.1(3.00) 21.8(2.14) 0.73 cholesterol approached statistical signifi-
Morethanhighschool 11.3(2.29) 14.2(1.40)* 0.29 canceintheNHANES1988–1994butes-
sentially disappeared by the NHANES
Dataare%(SE).SeenotestoTables1and2.FiguresstandardizedusingmethoddescribedinTable2.The
“other”racial/ethniccategoryisnotshown.*Thedifferencebetweenthereferencegroup(non-Latinowhite 1999–2008.Inthecaseofsmoking,post-
forraceandlessthanhighschoolforeducation)andeachraceoreducationgroupwithinthesameperiodis secondaryeducationandMexicanAmerican
statisticallysignificantwithP,0.05. ethnicitywereassociatedwithalowerrisk
of smoking in the NHANES 1999–2008
diabeteswere~50%morelikelythannon- population of individuals with diagnosed (Table 4, Current smoking column; Mexi-
Latinowhiteswithdiagnoseddiabetestobe diabetesatlarge,theseimprovementsmay canAmericanvs.non-Latinowhites:odds
inpoorglycemiccontrol(AfricanAmerican havebeen,tosomeextent,concentrated ratio0.66[95%CI=0.44–0.97];postsec-
vs.non-Mexicanwhite:oddsratio1.52 amongnon-Latinowhiteandmore-educated ondary education vs. no postsecondary
[95% CI 1.14–2.03]; Mexican vs. non- individuals,suchthatnewhealthdispar- education: 0.63 [0.42–0.95]). We did
Mexicanwhite:1.53[1.15–2.04]).Also,in itieshaveemerged. notfindtheseoddsratiosintheNHANES
the NHANES 1999–2008, we found that These racial/ethnic- and education- 1988–1994;surprisingly,having12years
individuals with postsecondary education relateddisparitiesinglycemiccontrolper- ofeducation (comparedwith ,12 years)
werelesslikelytobeinpoorglycemiccon- sisted when we limited the sample to the isassociatedwithahigherriskofsmoking
trolcomparedwiththosewithoutpostsec- most recent two waves of the NHANES intheNHANES1988–1994,althoughthe
ondary education (0.65 [0.48–0.89]). In (2005–2006and2007–2008)(resultsnot CIisverywideforthisestimate(Table4,
summary,ourresultsindicatethatalthough shown).Inthesemodels,wetriedinclud- Current smoking column; 2.34 [1.12–
glycemic control has improved in the ing covariates that may have captured 4.87]).
care.diabetesjournals.org DIABETESCARE,VOLUME35,FEBRUARY2012 309
DisparitiesinCVDriskfactorsindiabeticindividuals
Currentsmoking NHANESNHANES––988199419992008 1.001.00––(0.803.04)1.08(0.731.60)––(0.612.29)0.66(0.440.97)* 1.001.00––(1.124.87)*1.03(0.661.61)––(0.412.15)0.63(0.420.95)* hnicityandeducationareshown.Theear.Otherracial/ethnicminoritiesand–orNHANES19992008).Samplesizehschoolforeducation)andeachrace/ ciwtaAdNsrnheiobitfoHdsseirneuvpriitAtkvclTilearittiaNksroyhssdniheltueEiocilonaeioSAhmnhwlsfse1mtoosichdCw9ondkeeei8dVisd,retu8pihDNluwcnos–acdafHdr1eiarniinih9titaAaiseig9aoegTvkxNnv4snnsaaioE.-fobnm(wars2Sslgenceeiee3lndtoar1duo)4eetn.d9nreddT-sfid9daaoLihf9awbiodcafaub–eeuntihgscesti2slnenep,tty0seetoaoaoh.d0ssrsanRei2emiwatrniedipfecshoaoosetewdninhuonnitidngeeerr--t
d––Table4PoorlycontrolledCVDriskfactorsamongadultswithdiagnoseddiabetesinNHANES19881994andNHANES19992008 BloodpressureTotalcholesterolBloodglucose$$$7%)(130/80mmHg)(200mg/dL)(HbA1c NHANESNHANESNHANESNHANESNHANESNHANES––––––1988199419992008198819941999200819881994199920081 RaceNon-Latinowhite(reference)1.001.001.001.001.001.00––––––AfricanAmerican1.25(0.831.87)1.52(1.142.03)*1.37(0.832.24)1.33(0.991.79)0.83(0.561.23)0.90(0.701.16)1.56––––––MexicanAmerican1.38(0.932.06)1.53(1.152.04)*0.76(0.481.18)0.80(0.551.15)0.72(0.461.12)0.92(0.681.26)1.18EducationLessthanhighschool(reference)1.001.001.001.001.001.00––––––High-schoolgraduate1.44(0.882.37)0.75(0.521.09)0.79(0.521.22)0.97(0.661.43)0.81(0.491.33)1.00(0.701.42)2.34––––––Morethanhighschool1.01(0.641.60)0.65(0.480.89)*0.71(0.391.30)0.65(0.480.87)*1.59(1.022.49)*1.04(0.761.42)0.94 Dataareoddsratio(95%CI)fromlogisticmodelsinwhichadichotomousindicatorofpoorcontrolofariskfactoristhedependentvariable.Onlyoddsratiosrelatedtorace/etmodelsalsoincludecontrolsforage,sex,maritalstatus,yearssincediagnosisofdiabetes,obesity,iftherespondenthadaroutineplaceformedicalcare,insurancetype,andsurveyy–LatinoswhoarenotofMexicanoriginwereincludedinthenon-Latinowhitereferencegroupbecauseofsmallnumberofobservations(=33forNHANES19881994and=184fnn––is=1,065forNHANES19881994and=1,872forNHANES19992008.*Thedifferencebetweenthereferencegroup(non-Latinowhiteforrace/ethnicityandlessthanhignnfi,ethnicityoreducationgroupwithinsameperiodisstatisticallysignicantwith0.05.P ltga(ipaaPraN1(CwmbaurwaCcmiTtnncnwrcNtIagm1IepN1ednoirne2neaemmloodrrotmlr9e9yiorvo9oaheaeOVhyieHHhfiHsecegdeiameo4ennontdel8nt9scsons9eu1cnaiaooatnhfpsctvhnuD)eusepestia,AAtei8Aa-9aehrNactsO9sl.3annncretgrtxiolLiddpltldllcmeb–,i–widisoNNenceod/TetnN,–sledleggancsnoaerestusaC1,l2-l1etlnieramt,ho2otisiiHoixtiEEntirieaEcsri2rv9piatscn0niotmh2nlhhegLcmefnenn0ocdpgnwehla,hSSak,ciieS09C0eorrhd,eaxsondenddcdUnolts0rroipelaaoorer24atttelc8prap1aeiwieueeVis1uediofllhe,f8p1vnrocpdonv0wlstdta,stapSu9eostdr9adaDosp/ihhtfierr.eai9hdrllineogrucfreautdohrnde9nbld.ehdae8uIvnesaabyeeohsiloINee8ttftgdoalujec3suce9ddc,mOiaivut8enhnrctolstbeewwtswcn8ctnafieoeao8w–nHmPiaocsseia–cmtenpracohjtodaondt–nomunclNhpeai%lilr2chetrdsla1igiaasstfdAitnsdikiegaecn/dos1sodcor)hnorh0hauemvisrn9bepidbn.stde,etuunoiSNwndpb9niisldgoe0sarintboo9eesNr,tndletiultppvodrgoheseel-ni9ioehaledi8mTEitseglfss4ecissaeeerndttaokgltowiHlbsnnerd4atm.tsihaaStaetifidenssrpderieogeaeoorodtehr2iigtbbIfasiltenAtndiiAretflencs1tvaneiotiiakdfnednoniaen0eiileoionagendtoNdttcnsewitece9rrfiittbnitrg2,delsdonerlptfinthohadancusTiecaib8atiE4ibiesninttpd0asettgcsrchgsalcvlnetstecmlah.hlt8tthu.htllSeeoghnae,oihnraoaosmeaaelhbeohdddii(e–assTeldBvsaeesninfltnoncontoest17ole.sseyiategi1pievrohiehsee,tnwsstidudcmro,9,cnddd.reainlWneo9Ate2uopNeereiaogNNgso4ornh9Twglsiuaodemddei9io5en,lenamdmpnwpknw,oit9sbnHoeheHlHHwfiuimger4or,uhtiittrnrcinfvot–2dewfipiesaeiepesfnrrocefeArrnenoeloAArtsidgaolir2p.bn6oorisrncyeoaardsipyscemtroarsetdcnbgilNeieorNN0a)hloerussrceateOlcyelluvrvmti.juotssniuiuttttt0mieilsfivaoaeeefapecrirEnooEEeeahilihahheuvtddIcxinovsrsvrggaeoe8tceertslsrinndlnolSSSyyeeeeeeeeeessrr--------------f//.,.ll.
310 DIABETESCARE,VOLUME35,FEBRUARY2012 care.diabetesjournals.org
Chatterji,Joo,andLahiri
However, in the case of glycemic con- diabetestreatmentcomparedwithindivid- 3. AmericanDiabetesAssociation.Economic
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whites.Ratesofpoorglycemiccontrolfellby schooleducationreportedthattheirdoctor
5. Buse JB, Ginsberg HN, Bakris GL, et al.;
20%amongthosewith.12yearsofeduca- recommendedthattheymaintainanHbA
1c American Heart Association; American
tionbetweentheNHANES1988–1994and ,7% (the recommended level), whereas
DiabetesAssociation.Primaryprevention
theNHANES1999–2008,butratesofgly- only12% ofrespondents withless thana ofcardiovasculardiseasesinpeoplewith
cemic control remained stable during this high-school education reported that their diabetes mellitus: a scientific statement
time period among those with less than a doctors recommended this level. There fromtheAmericanHeartAssociationand
high-schooleducation.Resultsfromourre- alsoisevidencethatpeoplewhoaremore the American Diabetes Association. Cir-
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foranumberofconfoundingfactors,suggest rapidlythanpeoplewhoarelesseducated 6. Centers for Disease Control and Pre-
vention.NationalDiabetesFactSheet:Na-
thatAfricanAmericansandMexicanAmer- (28). Third, culture and language may
tionalEstimatesandGeneralInformationon
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NHANES1999–2008were50%morelikely ces, andthese factors may underlie racial/ Diabetes and Prediabetes in the United
States, 2011. Atlanta, GA, U.S. Depart-
tohavepoorglycemiccontrolthannon- ethnicdisparitiesinoutcomes(11).
ment of Health and Human Services,
Latinowhiteswithdiagnoseddiabetes. Although the mechanisms through Centers for Disease Control and Pre-
Moreover,intheNHANES1999–2008, whichsociodemographiccharacteristicsaf- vention,2011
individuals with diabetes who had at least fect control of CVD risk factors are un- 7. AmericanDiabetesAssociation.Standards
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notstatisticallysignificant.Italsoisnotable controlofCVDriskfactorsamongindivid- Detection,Evaluation,andTreatmentofHigh
BloodCholesterolinAdults(AdultTreatment
that smoking rates amongindividuals with ualswithdiabetes,italsoistruethatonlya
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withotherdata(27).
In summary, our findings show that AcknowledgmentsdThis research was sup- tcwoneetrnol:ceovnitdinenuciteyfroofmctahreeTahnirddNdiaatbioenteasl
important progress has been made in re-
ported by the National Institute on Minority Health and Nutrition Examination Sur-
ducingCVDriskfactorsamongindividuals HealthandHealthDisparities,NationalInstitutes vey.AmJPublicHealth2004;94:66–70
with diagnosed diabetes overthe past de- ofHealth(grantno.1-P20-MD-003373). 11. TwoFeathersJ,KiefferEC,PalmisanoG,
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