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Expressed racial identity and hypertension in a telephone survey sample from Toronto and Vancouver, Canada:… Veenstra, Gerry Oct 12, 2012

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RESEARCH Open AccessExpressed racial identity and hypertension in atelephone survey sample from Toronto andVancouver, Canada: do socioeconomic status,perceived discrimination and psychosocial stressexplain the relatively high risk of hypertension forBlack Canadians?Gerry VeenstraAbstractIntroduction: Canadian research on racial health inequalities that foregrounds socially constructed racial identitiesand social factors which can explain consequent racial health inequalities is rare. This paper adopts a socialtypology of salient racial identities in contemporary Canada, empirically documents consequent racial inequalities inhypertension in an original survey dataset from Toronto and Vancouver, Canada, and then attempts to explain theinequalities in hypertension with information on socioeconomic status, perceived experiences with institutionalizedand interpersonal discrimination, and psychosocial stress.Methods: Telephone interviews were conducted in 2009 with 706 randomly selected adults living in the City ofToronto and 838 randomly selected adults living in the Vancouver Census Metropolitan Area. Bivariate analyses andlogistic regression modeling were used to examine relationships between racial identity, hypertension,socio-demographic factors, socioeconomic status, perceived discrimination and psychosocial stress.Results: The Black Canadians in the sample were the most likely to report major and routine discriminatoryexperiences and were the least educated and the poorest. Black respondents were significantly more likely thanAsian, South Asian and White respondents to report hypertension controlling for age, immigrant status and city ofresidence. Of the explanatory factors examined in this study, only educational attainment explained some of therelative risk of hypertension for Black respondents. Most of the risk remained unexplained in the models.Conclusions: Consistent with previous Canadian research, socioeconomic status explained a small portion of therelatively high risk of hypertension documented for the Black respondents. Perceived experiences of discriminationboth major and routine and self-reported psychosocial stress did not explain these racial inequalities inhypertension. Conducting subgroup analyses by gender, discerning between real and perceived experiences ofdiscrimination and considering potentially moderating factors such as coping strategy and internalization of racialstereotypes are important issues to address in future Canadian racial inequalities research of this kind.Keywords: Canada, Racial identity, Hypertension, Socioeconomic status, Perceived discrimination, PsychosocialstressCorrespondence: gerry.veenstra@ubc.caDepartment of Sociology, The University of British Columbia, Vancouver,British Columbia, Canada© 2012 Veenstra; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the CreativeCommons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, andreproduction in any medium, provided the original work is properly cited.Veenstra International Journal for Equity in Health 2012, 11:58http://www.equityhealthj.com/content/11/1/58IntroductionHypertension is one of the most common chronic dis-eases in modern-day western societies. In Canada, morethan one in five adults lives with the disease [1]. In theUnited States, almost one-third of adults aged 20 andover is hypertensive [2]. A large body of research hasestablished the existence of sizeable racial inequalities inhypertension in the latter nation, one notable facet ofwhich is the elevated risk of hypertension for AfricanAmericans compared to White Americans. Data fromthe U.S. National Health and Nutrition ExaminationSurvey (NHANES) reveal rates of hypertension in 1988–1994 that are 1.4 times as high among Black men thanamong White men and 1.8 times as high among Blackwomen than among White women [3]. More recentstudies have determined that the Black-White gap inhypertension in the United States is not shrinking andmay even be widening [4].Various explanations have been proposed for thepersistent Black-White gap in hypertension in the UnitedStates, including the residential segregation of racialminorities, differences in socioeconomic status, differen-tial access to quality health care, internalization by racialminorities of the larger society’s negative characteriza-tions of them, and the psychosocial stress that can resultfrom experiences of interpersonal racism and discrimin-ation [3]. All of these explanations have received empir-ical attention from American researchers, albeit todifferent degrees. The mediating role played by socioe-conomic status in Black-White differences in hyperten-sion has been the most extensively investigated. Manyresearchers have found that socioeconomic statusexplains some of the Black-White gap in hypertension[5,6]. It does not, however, explain the entirety of thegap [7,8], inviting other explanations. Subjective per-ceptions regarding experiences of discrimination havereceived attention in recent years as another plausibleexplanation for Black-White differences in hypertensionin the United States. Researchers posit that chronic ex-posure to perceived interpersonal discrimination inducesa psychosocial stress which in turn elevates blood pres-sure. A review of the literature on perceived racism andblood pressure finds that the American evidence linkingperceived racism and discrimination to blood pressure ingeneral is mixed [9]. Most of the relevant studies exam-ine linkages between perceived discrimination and bloodpressure within rather than between racial groupings.One notable study, however, examined the degree towhich perceived discrimination explained Black-Whitedifferences in hypertension [10]: it found that Black-Whitedifferences were wider among working-class womenreporting some discrimination than among working-classwomen reporting none, a result that runs contrary to thepsychosocial stress hypothesis. Scholars have posited thatperceived racism may only adversely affect blood pressurein certain conditions, e.g., when the people perceiving thediscrimination are disposed to actively cope with thediscrimination and overcome adversity [11] or whenthey do not internalize negative stereotypes about theirown racial group [12]. Research in this complex field ofinquiry continues.In contrast with the laudable efforts of the Americanhealth research community, racial inequalities in hyper-tension in Canada have yet to receive sustained attentionfrom health researchers. This may reflect reluctance onthe part of the Canadian health research community tocountenance the possibility of health inequalities by‘race’ in this supposedly egalitarian, multicultural andtolerant society. But Canada is not egalitarian or toler-ant, and racial health inequalities do in fact exist here, asdocumented in a small number of empirical studies[13-20]. With regard to hypertension in particular, oneof the studies reported an age-adjusted prevalence ofhypertension of 17.1% for White Canadians comparedto an age-adjusted prevalence of 23.9% for Black Canadians[19]. Another nationally representative study found thatBlack Canadians had odds of reporting hypertension thatwere 1.56 times as high as those of White Canadianscontrolling for age and gender, a relationship that wasnot explained by socioeconomic status or urban versusrural locale [15]. Overall, however, little is currentlyknown about the nature of racial differences in hyperten-sion in Canada and, to the degree that they exist, theviability of the different possible explanations for them.Accordingly, this paper adopts a social typology ofsalient racial identities in contemporary Canada, empir-ically documents racial inequalities in hypertension inan original survey dataset from Toronto and Vancouver,Canada, and then attempts to explain the inequalitieswith information on socioeconomic status, perceivedexperiences with institutionalized and interpersonal dis-crimination, and psychosocial stress. It extends toCanada a line of inquiry already well established in theUnited States and elsewhere, thereby contributing tothe illumination of racial inequalities in hypertension inCanada and the viability of several proposed explanationsfor them.MethodsSurvey sampleIn 2009, the Survey Research Centre (SRC) at the Uni-versity of Victoria conducted telephone interviews with732 adults living in the City of Toronto and 863 adultsliving in the Vancouver Census Metropolitan Area. Thesurvey was approved by the Research Ethics Board at theUniversity of British Columbia. The SRC used random-digit dialing techniques to obtain residential telephonenumbers, a next-birthday strategy to select one residentVeenstra International Journal for Equity in Health 2012, 11:58 Page 2 of 10http://www.equityhealthj.com/content/11/1/58per household aged 19 or older to interview and acomputer-aided telephone interviewing system to con-duct the interviews. The racial identities of the inter-viewers were not recorded. The cooperation rate was9.3%. A total of 1,544 respondents (96.8% of the full sam-ple) had non-missing information for all of hypertension,age, gender, marital status, city of residence, immigrantstatus, educational attainment and psychosocial stress.Characteristics of this working sample are described inTable 1. Comparing the city samples to the 2006 Censusby age, gender, marital status, immigrant status and edu-cation, both city samples were biased towards olderpeople, women, non-immigrants and university-educatedpeople. In addition, the Toronto sample was biased to-wards unmarried people and the Vancouver sample wasbiased towards married people.Survey measures‘Expressed racial identity’ refers to a person’s self-identification with a racial grouping that s/he will expressto others when asked to fit into ‘official’ racial classifica-tions presented by Census forms, survey researchers,insurance forms, and so forth [16,21]. To measureexpressed racial identity interviewees were asked: “NowI’d like to ask you about your racial background. Howwould you describe your racial background? For example,are you White, Asian, South Asian, Black, SoutheastAsian, or Aboriginal, or perhaps something else I haven’tmentioned? Please feel free to provide more than one an-swer if you have several backgrounds.” Due to the smallnumber of respondents who chose Aboriginal or South-east Asian identity (Table 1), the expressed racial identityvariable was subsequently recoded as Asian, Black, SouthAsian, White, and Other for these analyses.Interviewers asked fifteen questions pertaining toexperiences of discrimination. The items were adaptedfrom the Major Experiences of Discrimination scale andthe Everyday Discrimination Scale created by Williamsand colleagues [22] and utilized by numerous others e.g.,[23-25]. The items are intended to measure majorexperiences of unfair treatment as well as chronic, rou-tine experiences of unfair treatment in everyday life. Thepreamble to the questions went as follows: “Now let’s goin a different direction. The following questions we willask are personal in nature and may make you feel un-comfortable. Your responses will be kept in the strictestof confidence. We are interested in your opinions abouthow other people have treated you. Can you tell me ifany of the following has ever happened to you?” Respon-dents were asked seven questions pertaining to majorexperiences of unfair treatment: 1. “For unfair reasons,have you ever not been hired for a job?” 2. “Have youever been unfairly denied a promotion at work?” 3.” Doyou feel you have been unfairly fired or let go from ajob?” 4. “Have you ever moved into a neighborhoodwhere neighbors made life difficult for you or your fam-ily?” 5. “Have you ever received service from someonesuch as a plumber or car mechanic that was worse thanwhat other people get?” 6. “Have you ever been unfairlydenied a bank loan, a mortgage, or insurance?” 7. “Haveyou ever been unfairly questioned, searched, or threa-tened by the police?” An alpha of 0.516 indicates thatthese dichotomous items did not form an internallycoherent scale. An index of major discriminatory experi-ences was created that distinguished between three ormore, two, one and no major experiences.Each time a respondent responded in the affirmativeto a major discriminatory experience question they werethen asked “What do you think was the main reason forthis experience?” The following possible responses wereread aloud by interviewers in random order: Your gen-der, your age, your ethnic or racial background, yourheight, your weight, your religion, your education, yourincome level, a physical disability, your sexual orienta-tion, other. From this a measure of racial/ethnic majordiscriminatory experiences in particular was created thatdistinguished between two or more experiences, oneexperience and no experiences of discrimination attrib-uted by respondents to their racial/ethnic identities.Respondents were also asked: “In your day-to-day life,how often do the following things happen to you?” 1.“You are treated with less respect or courtesy than otherpeople.” 2. “You receive poorer service than other peopleat restaurants or stores.” 3. “People act as if they thinkyou are not smart.” 4. “People act as if they think youare dishonest.” 5. “People act as if they think they arebetter than you.” 6. “People act as if they are afraid ofyou.” 7. “You are called names or insulted by people.”and 8. “You are threatened or harassed by people.” Pos-sible responses to these questions were: almost everyday, at least once a week, a few times a month, a fewtimes a year, and never. An index of self-reported every-day discrimination was created by summing theresponses to these questions (0 = never, 1 = a few timesa year, 2 = a few times a month, 3 = at least once a weekand 4 = almost every day) into a variable ranging from 0to 22 with a mean of 3.205 and a standard deviation of3.595 (n = 1490). An alpha of 0.794 indicates thatrespondents who experienced one form of routine dis-crimination were relatively likely to have experiencedothers as well, perhaps indicative of a latent factor per-taining to susceptibility to routine forms of discrimin-ation more generally. This variable was subsequentlyrecoded into categorical form as shown in Table 1.Respondents were asked “What is the highest level ofeducation you have completed?” with response categor-ies that ranged from less than high school to a com-pleted postgraduate degree. This variable was coded toVeenstra International Journal for Equity in Health 2012, 11:58 Page 3 of 10http://www.equityhealthj.com/content/11/1/58Table 1 Characteristics of the sample (n=1,544)Variable City of residenceToronto Vancouvern(%) n(%)Expressed racial identity Aboriginal 3(0.4) 4(0.5)Asian 20(2.8) 50(6.0)Black 45(6.4) 2(0.2)South Asian 26(3.7) 42(5.0)Southeast Asian 10(1.4) 10(1.2)White 539(76.4) 683(81.5)Other 16(2.3) 19(2.3)multiple responses 20(2.8) 12(1.4)missing 27(3.8) 16(1.9)Age aged 19-34 144(20.4) 104(12.4)aged 35-44 133(18.8) 137(16.4)aged 45 - 54 163(23.1) 199(23.8)aged 55-64 141(20.0) 255(26.9)aged 65 and other 125(17.7) 173(20.6)Gender male 251(35.6) 274(32.7)female 455(64.4) 564(67.3)Marital status married or common law 368(52.1) 522(62.3)separated, divorced or widowed 161(22.8) 189(22.6)never been married 177(25.1) 127(15.2)Immigrant status born in Canada 457(64.7) 608(72.6)immigrated > 20 years ago 169(23.9) 152(18.1)immigrated between 10 and 20 years ago 39(5.5) 41(4.9)immigrated < 10 years ago 41(5.8) 37(4.4)Educational attainment high school or less 157(22.2) 235(28.0)CC, TS or some university 160(22.7) 257(30.7)bachelor’s degree 237(33.6) 216(25.8)post - graduate degree 152(21.5) 130(15.5)Household income less than $40,000 110(15.6) 130(15.5)$40,000 - $59,999 89(12.6) 98(11.7)$60,000 - $79,999 103(14.6) 99(11.7)$80,000 - $99,000 72(10.2) 89(10.6)$100,000 - $149,999 101(14.3) 151(18.0)$150,000 or more 124(17.6) 121(14.4)missing 107(15.2) 150(17.9)Major discrimination no experiences 276(39.1) 384(45.8)one experience 194(17.5) 201(24.0)two experiences 106(15.0) 116(13.8)three or more experiences 88(12.5) 105(12.5)missing 42(6.0) 32(3.8)Racial/ethnic major discriminatory experiences no experiences 588(83.3) 735(87.7)one experience 55(7.8) 57(6.8)two or more experiences 21(3.0) 14(1.7)missing 42(6.0) 32(3.8)Veenstra International Journal for Equity in Health 2012, 11:58 Page 4 of 10http://www.equityhealthj.com/content/11/1/58distinguish between high school or less; community col-lege, technical school or some university; bachelor’s de-gree at university; and postgraduate degree. To measureincome, respondents were asked: “What is your best es-timate of the total income of all household members –including yourself – in the year 2008, before taxes anddeductions? Please be sure to include income from allsources.” A set of income ranges provided to respon-dents culminated in an upper category representinghousehold incomes of $150,000 or higher (see Table 1).To measure psychosocial stress, respondents wereasked “Thinking about the amount of stress in your life,would you say that most days are: not at all stressful? abit stressful? quite stressful? extremely stressful?” The lat-ter two categories were combined due to small cell sizes.Finally, respondents were asked: “Now I’d like to askyou about certain health conditions you may have. Doyou have high blood pressure or hypertension?” If yes,they were asked: “Was your high blood pressure diag-nosed by a physician?” Three hundred and six (19.8%)respondents reported hypertension, in all but sevencases diagnosed as such by a physician.Statistical analysisThe statistical analyses were conducted in Stata 11.2.Missing data categories were created for household in-come (n = 257), major experiences of discrimination(n = 74) and routine experiences of discrimination (n = 54).Bivariate relationships were investigated via comparisonsof means with one-way ANOVA tests of significance andcross-tabulations with Chi-square tests of significance.Multivariate analyses involved binary logistic regressionmodeling of the presence of hypertension. The surveyfunctionality of Stata was used to properly account forthe complex survey design – two cities of different popu-lation sizes; different numbers of households randomlysampled within the two cities; sampling without replace-ment rather than with replacement when samplinghouseholds; one adult randomly selected from eachhousehold – in the regression modeling. This ensuredthat the correct sampling weights were used when gener-ating point estimates and that the weighting, clusteringand stratification characteristics of the survey designwere properly accommodated when generating standarderrors.ResultsPreliminary analysesTable 2 describes bivariate relationships between socio-demographic characteristics, socioeconomic status, self-reported discrimination and psychosocial stress and theprimary independent (expressed racial identity) anddependent (hypertension) variables. With regard tosocio-demographic characteristics, expressed racial identitywas significantly related to age (F = 35.24, df = 4, 1539,p < 0.001), with Black respondents the youngest andWhite respondents the oldest, on average; gender (Chi-square = 18.68, df = 4, p < 0.01), with the lowest propor-tion of women among South Asian respondents and thehighest among Black respondents; marital status (Chi-square = 63.83, df = 8, p < 0.001), with South Asianrespondents most likely and Black respondents leastlikely to be married or common-law; immigrant status(Chi-square = 388.20, df = 12, p < 0.001), with Whiterespondents much more likely than others to be born inCanada and South Asian respondents most likely to berecent immigrants; city of residence (Chi-square = 63.76,df = 4, p < 0.001), with nearly all Black respondentsliving in Toronto and most Asian respondents livingin Vancouver; education (Chi-square = 33.56, df = 12,p < 0.01), with Black respondents least and Asianrespondents most educated; and income (Chi-square =63.69, df = 24, p < 0.001), with Black respondents thepoorest and White respondents the wealthiest. Withregard to perceived discrimination, expressed racialidentity was significantly related to major discriminatoryexperiences (Chi-square = 37.77, df = 16, p < 0.01), majorracial/ethnic discriminatory experiences (Chi-square =202.10, df = 12, p < 0.001) and routine discriminatoryexperiences (Chi-square = 82.29, df = 20, p < 0.001), withBlack respondents reporting the most discriminatoryexperiences of all kinds, Asian and White respondentsreporting the fewest major discriminatory experiencesTable 1 Characteristics of the sample (n=1,544) (Continued)Routine discrimination index 0 148(21.0) 226(27.0)1 or 2 194(27.5) 250(29.8)3 or 4 131(18.6) 147(17.5)5 or greater 205(29.0) 189(22.6)missing 28(4.0) 26(3.1)Daily stress not stressful 99(14.0) 161(19.2)a bit stressful 367(52.0) 437(52.2)quite or extremely stressful 240(34.0) 240(28.6)Veenstra International Journal for Equity in Health 2012, 11:58 Page 5 of 10http://www.equityhealthj.com/content/11/1/58Table 2 Correlates of expressed racial identity and hypertensionVariable Expressed racial identity HypertensionAsian Black South Asian White Other yes noAge in years - n (sd) 42.5(14.3) 40.5(11.2) 41.1(14.1) 53.6(14.8) 44.6(15.2) 61.75(12.5) 48.7(14.8)F = 35.24, df = 4,1539, p < 0.001 F = 200.43, df = 1, 1542, p < 0.001Gender female n (%) 50(71.4) 37(78.7) 31(45.6) 817(66.9) 84(61.3) 196(19.2) 823(80.8)male 20(28.6) 10(21.3) 37(54.4) 405(33.1) 53(38.7) 110(20.9) 415(79.1)Chi - square = 18.68, df = 4, p < 0.01 Chi - square = 0.64, df = 1, p > 0.10Marital status married or common law 32(45.7) 16(34.0) 47(69.1) 716(58.6) 79(57.7) 157(17.6) 733(82.4)separated, divorcedor widowed10(14.3) 9(19.2) 9(13.2) 303(24.8) 19(13.9) 114(32.6) 236(67.4)never been married 28(40.0) 22(46.8) 12(17.7) 203(16.6) 39(28.5) 35(11.5) 269(88.5)Chi - square = 63.83, df = 8, p < 0.001 Chi - square = 51.67, df = 2, p < 0.001Immigrantstatusborn in Canada 17(24.3) 12(25.5) 15(22.1) 962(78.7) 59(43.1) 211(19.8) 854(80.2)immigrated > 20 yearsago23(32.9) 24(51.1) 21(30.9) 213(17.4) 40(29.2) 81(25.2) 240(74.8)immigrated between10 and 20 years ago16(22.9) 6(12.8) 15(22.1) 22(1.8) 21(15.3) 8(10.0) 72(90.0)immigrated < 10 yearsago14(20.0) 5(10.6) 17(25.0) 25(2.1) 17(12.4) 6(7.7) 72(92.3)Chi - square = 388.20, df = 12, p < 0.001 Chi - square = 17.99, df = 3, p < 0.001City of residence Toronto 20(28.6) 45(95.7) 26(38.2) 539(44.1) 76(55.5) 123(17.4) 583(82.6)Vancouver 50(71.4) 2(4.3) 42(61.8) 683(55.9) 61(44.5) 183(21.8) 655(78.2)Chi - square = 63.76, df = 4, p < 0.001 Chi - square = 4.70, df = 1, p < 0.05Educationalattainmenthigh school or less 11(15.7) 18(38.3) 16(23.5) 318(26.0) 29(21.2) 95(24.3) 297(75.8)CC, TS or some university 12(17.1) 16(34.0) 15(22.1) 328(26.8) 46(33.6) 93(22.3) 324(77.7)bachelor’s degree 35(50.0) 12(25.5) 21(30.9) 343(28.1) 42(30.7) 76(16.8) 377(83.2)post - graduate degree 12(17.1) 1(2.1) 16(23.5) 233(19.1) 20(14.6) 42(14.9) 240(85.1)Chi - square = 33.56, df = 12, p < 0.01 Chi - square = 13.37, df = 3, p < 0.01Householdincomeless than $40,000 9(12.9) 17(36.2) 8(11.8) 181(14.8) 25(18.3) 58(24.2) 182(75.8)$40,000 - $59,999 15(21.4) 6(12.8) 10(14.7) 144(11.8) 12(8.8) 41(21.9) 146(78.1)$60,000 - $79,999 8(11.4) 6(12.8) 8(11.8) 158(12.9) 22(16.1) 33(16.3) 169(83.7)$80,000 - $99,000 7(10.0) 3(6.4) 10(14.7) 128(10.5) 13(9.5) 26(16.2) 135(83.9)$100,000 - 149,999 8(11.4) 5(10.6) 8(11.8) 216(17.1) 15(11.0) 50(19.8) 202(80.2)$150,000 or more 4(5.7) 1(2.1) 8(11.8) 217(17.8) 15(11.0) 43(17.6) 202(78.6)missing 19(27.1) 9(19.2) 16(23.5) 178(14.6) 35(25.6) 55(21.4) 202(78.6)Chi -square = 63.69, df = 24, p < 0.001 Chi - square = 7.48, df = 6, p > 0.10Majordiscriminationno experiences 37(52.9) 14(29.8) 30(44.1) 534(43.7) 45(32.9) 130(19.7) 530(80.3)one experience 19(27.1) 7(14.9) 15(22.1) 315(25.8) 39(28.5) 85(21.5) 310(78.5)two experiences 7(10.0) 9(19.2) 9(13.2) 177(14.5) 20(14.6) 44(19.8) 178(80.2)three or moreexperiences2(2.9) 10(21.3) 10(14.7) 149(12.2) 22(16.1) 37(19.2) 156(80.8)missing 5(7.1) 7(14.9) 4(5.9) 47(3.9) 11(8.0) 10(13.5) 64(86.5)Chi - square = 37.77, df = 16, p < 0.01 Chi - square = 2.63, df = 4, p > 0.10Racial/ethnicmajordiscriminatoryexperiencesno experiences 51(72.9) 21(44.7) 43(63.2) 1113(91.1) 95(69.3) 274(20.7) 1049(79.3)one experience 9(12.9) 12(25.5) 13(19.1) 57(4.7) 21(15.3) 16(14.3) 96(85.7)two or moreexperiences5(7.1) 7(14.9) 8(11.8) 5(0.4) 10(7.3) 6(17.1) 29(82.9)missing 4(7.1) 7(14.9) 4(5.9) 47(3.9) 11(8.0) 10(13.5) 64(86.5)Chi - square = 202.10, df = 12, p < 0.001 Chi - square = 4.83, df = 3, p > 0.10Veenstra International Journal for Equity in Health 2012, 11:58 Page 6 of 10http://www.equityhealthj.com/content/11/1/58and White respondents reporting the fewest routinediscriminatory experiences.With regard to risk of hypertension and socio-demographic characteristics, there was a strong expo-nential effect of age on the likelihood of reporting hyper-tension (comparison of mean ages produced F = 200.43,df = 1, 1542, p < 0.001). Hypertension was also signifi-cantly related to marital status (Chi-square = 51.67, df =2, p < 0.001), with respondents who had never beenmarried the least likely to report hypertension, a resultthat is a function of age (results not shown); immigrantstatus (Chi-square = 17.99, df = 3, p < 0.001), where,consistent with the healthy immigrant effect, recentimmigrants were the least likely to report hypertensionand longstanding immigrants were the most likely to doso; city of residence (Chi-square = 4.70, df = 1, p <0.05), with Vancouver residents more likely than To-ronto residents to report hypertension; and education(Chi-square = 13.37, df = 3, p < 0.01), with better-educated respondents the less likely to report hyperten-sion. With regard to perceived discrimination, the majordiscriminatory experiences (Chi-square = 2.63, df =4, p > 0.10), racial/ethnic experiences of discrimin-ation (Chi-square = 4.83, df = 3, p > 0.10) and psy-chosocial stress (Chi-square = 5.46, df = 2, p > 0.05)variables were not significantly related to hyperten-sion. Surprisingly, routine discriminatory experienceswere related to hypertension in the unexpecteddirection wherein more perceived discrimination ofthis kind corresponded with a lower likelihood ofreporting high blood pressure (Chi-square = 11.28,df = 4, p < 0.05).Findings from these preliminary analyses indicate theimportance of controlling for age, immigrant status andcity of residence in an investigation of relationshipsbetween expressed racial identity and hypertension.They also speak to the plausibility of educational attain-ment and routine discriminatory experiences, and theimplausibility of household income, major experiencesof discrimination, racial/ethnic discrimination, and psy-chosocial stress, as mediating factors in causal pathwaysfrom expressed racial identity to hypertension in thissample.Modeling hypertensionTable 3 describes the results from a series of three bin-ary logistic regression models performed on hyperten-sion. The first model controls for age, immigrant statusand city of residence, the second model additionally con-trols for educational attainment and the third modeladds the routine discrimination variable to the secondmodel.Ten of 70 (14.3%) Asian respondents, 12 of 47 (25.5%)Black respondents, 6 of 68 (8.8%) South Asian respon-dents and 253 of 1,222 (20.7%) White respondentsreported hypertension. Controlling for age, marital sta-tus, immigrant status and city of residence in Model 1,Black respondents were significantly more likely thanWhite respondents (OR = 5.16, 95% CI = 2.26 . . . 11.77,p < 0.001) to report hypertension. (Black Canadianrespondents were also significantly more likely thanAsian Canadian respondents (OR = 5.41, 95% CI = 1.86. . . 15.70, p < 0.01) and South Asian Canadian respon-dents (OR = 8.85, 95% CI = 2.80 . . . 27.93, p < 0.001) toreport hypertension when Asian and South Asian, re-spectively, replaced White as the reference category.)The Black-White odds ratio was marginally attenuatedupon additionally controlling for education (OR = 4.42,95% CI = 1.90 . . . 10.29, p < 0.01). Additionally control-ling for routine discriminatory experiences did not sub-stantially reduce the effect (OR = 4.22, 95% CI =1.80 . . . 9.88, p < 0.01).In summary, Black respondents manifested relativelyhigh risks of hypertension compared with Asian, SouthAsian and White respondents. Of the possible explana-tory factors examined in this study, only educationalattainment explained some of the risk of hypertension forTable 2 Correlates of expressed racial identity and hypertension (Continued)Routinediscriminationindex0 14(20.0) 2(4.3) 13(19.1) 316(25.9) 29(21.2) 79(21.1) 295(78.9)1 or 2 18(25.7) 6(12.8) 24(35.3) 368(30.1) 28(20.4) 97(21.9) 347(78.2)3 or 4 10(14.3) 11(23.4) 7(10.3) 233(19.1) 17(12.4) 56(20.1) 222(79.9)5 or greater 22(31.4) 24(51.1) 21(30.9) 278(22.8) 49(35.8) 58(14.7) 336(85.3)missing 6(8.6) 4(8.5) 3(4.4) 27(2.2) 14(10.2) 16(29.6) 38(70.4)Chi - square = 82.29, df = 20, p < 0.001 Chi - square = 11.28, df = 4, p < 0.05Daily stress not stressful 10(14.3) 8(17.0) 16(23.5) 201(16.5) 25(18.3) 65(25.0) 195(75.0)a bit stressful 44(62.9) 26(55.3) 35(51.5) 626(51.2) 73(53.3) 148(18.4) 656(81.6)quite or extremelystressful16(22.9) 13(27.7) 17(25.0) 395(32.3) 39(28.5) 93(19.4) 387(80.6)Chi - square = 7.64, df = 8, p > 0.10 Chi - square = 5.46, df = 2, p > 0.05Veenstra International Journal for Equity in Health 2012, 11:58 Page 7 of 10http://www.equityhealthj.com/content/11/1/58Black respondents relative to the others. Most of the riskremained unexplained in these analyses.DiscussionLimitationsLimitations of the study include the use of self-reportedmeasures of health and a crude measure of self-reportedpsychosocial stress. The racial identity labels assessedin the study may not perfectly reflect current processesof racialization in this country; careful examination ofCanadian media and interviews with a multitude ofCanadians from all walks of life are needed in order toascertain the terms and concepts that Canadians tendto use to map the fluid, ever-changing racial landscapein contemporary Canadian society [16]. Also, as in mostsurvey research of this kind, the racial identity labelswere attached to survey respondents on the basis of theirown perceptions and affiliations. This means that, to thedegree that key racialized identities in Canadian societywere misidentified and/or imputed racialized identitiesand self-professed racial identities are incongruent withone another, serious measurement error exists. It is alsoworth noting that the measures of discrimination did notassess age of first onset and addressed a limited set ofdomains [3]. The cooperation rate was low bringingissues of representativeness into play. Another limitationof the study pertained to the small numbers of self-expressed Black respondents (n = 47) and self-expressedAsian respondents (n = 68) which limited the number ofindependent variables in the multivariate models andprevented subgroup analyses by gender or immigrantstatus. The exceedingly small numbers of Aboriginal(n = 7) and Southeast Asian (n = 20) respondents pre-vented any investigation of their relative risks of report-ing hypertension, an especially important limitationgiven recent Canadian research which has identifiedrelatively high risks of hypertension accruing to theseidentities [15].Study findingsThe Black Canadians in the sample were the most likelyto report major and routine discriminatory experiencesTable 3 Binary logistic regression models on hypertensionModel 1 Model 2 Model 3OR 95% Cl OR 95% Cl OR 95% ClExpressed racial identity Asian 0.95 0.41 .. 2.21 0.95 0.40 .. 2.27 0.94 0.39 .. 2.29Black 5.16*** 2.26 .. 11.77 4.42** 1.90 .. 10.29 4.22** 1.80 .. 9.88South Asian 0.58 0.22 .. 1.54 0.59 0.21 .. 1.64 0.59 0.21 .. 1.62Other 1.77 0.95 .. 3.31 1.74 0.93 .. 3.26 1.74 0.91 .. 3.31White(reference) 1.00 1.00 1.00Age in years ——— 1.26*** 1.16 .. 1.37 1.26*** 1.16 .. 1.37 1.26*** 1.16 .. 1.38Age in years squared ——— 1.00*** 1.00 .. 1.00 1.00*** 1.00 .. 1.00 1.00*** 1.00 .. 1.00Immigration status immigrated > 20 years ago 1.05 0.72 .. 1.55 1.11 0.75 .. 1.63 1.11 0.75 .. 1.64immigrated 10–19 years ago 1.44 0.53 .. 3.91 1.54 0.55 .. 4.28 1.51 0.54 .. 4.23immigrated < 10 years ago 1.42 0.56 .. 3.58 1.70 0.67 .. 4.36 1.74 0.68 .. 4.43born in Canada(reference) 1.00 1.00 1.00City of residence Vancouver 1.23 0.90 .. 1.68 1.17 0.85 .. 1.60 1.18 0.85 .. 1.63Education high school or less ——— ——— 0.80 0.53 .. 1.20 2.01** 1.24 .. 3.27c c/ts/come university ——— ——— 0.64* 0.42 .. 0.98 1.59 0.98 .. 2.58bachelor degree ——— ——— 0.50** 0.31 .. 0.81 1.29 0.79 .. 2.11post-graduate degree(reference)——— ——— 1.00 1.00Routine discrimination scale 1 or 2 ——— ——— ——— ——— 1.10 0.73 .. 1.673 or 4 ——— ——— ——— ——— 1.28 0.78 .. 2.085 or greater ——— ——— ——— ——— 1.24 0.76 .. 2.03missing ——— ——— ——— ——— 1.17 0.54 .. 2.540 (reference) ——— ——— ——— ——— 1.00N 1,544 1,544 1,544f test (F, df, p) F = 13.21, df = 10, 1533,p < 0.001F = 10.68, df = 13, 1530,p < 0.001F = 8.20, df = 17, 1526,p < 0.001MacFadden pseudo R - squared 0.142 0.146 0.149Veenstra International Journal for Equity in Health 2012, 11:58 Page 8 of 10http://www.equityhealthj.com/content/11/1/58and were the least educated and the poorest. Theseresults, evidence of multiple kinds of systematic racismregularly encountered by Black Canadians, are consistentwith previous research in Canada. For example, otherstudies have also reported that Black Canadians earnsignificantly less than White Canadians [26,27] and arethe racial group most likely to report discrimination [28].A relatively high risk of hypertension for Black Cana-dians also emerged in these data: controlling for age,immigrant status and city of residence, the odds of aBlack respondent reporting hypertension were more thanfive times as high as those for Asian, South Asian andWhite respondents. The relatively high risk of hyperten-sion among the Black respondents compared to theWhite respondents is consistent with previous researchin the United States [3,9-11,29,30] and Canada [15,19].Regarding potentially explanatory factors, the risk ofhypertension for the Black Canadians was partly explainedby education; none of the other factors meaningfully atte-nuated the relationship. The inability of self-reportedexperiences of discrimination to explain the racial inequal-ities in hypertension may reflect a lack of attention in thestudy to moderating factors that influence how a persondeals with or reacts to perceived discrimination. Forexample, James [11] suggests that ‘high effort’ copingwith psychosocial stressors produces increases in bloodpressure, suggesting that the manner in which someoneresponds to perceived racism moderates its effects. Alongsimilar lines, Chae and colleagues [12] found no relation-ship between perceptions of racial discrimination andcardiovascular disease in a sample of African Americanmen but discovered that racial discrimination was posi-tively associated with cardiovascular disease among themen who did not subscribe to negative views aboutBlacks and negatively associated among the men who didsubscribe to such views. This means that beliefs and per-ceptions about the relative worth of racial identities insociety may also be enmeshed with discrimination as pre-dictors of health. In short, discrimination may engenderhypertension among Black Canadians who actively con-front the racism, who identify themselves more stronglyas Black and/or who believe that the racism is unfair andunjust; unfortunately, this study could not investigatethese possibilities.ConclusionsOnly educational attainment explained some of the highrisk of hypertension for the Black Canadians in this sam-ple, throwing the viability of self-reported discriminationand psychosocial stress as explanations for racial inequal-ities in hypertension in doubt in this context. Conductingsubgroup analyses by gender, discerning between real andperceived experiences of discrimination and incorporatingconsideration of potentially moderating factors such ascoping strategy and internalization of racial stereotypesare important issues to address in future Canadian racialinequalities research.Competing interestsI have no competing interests regarding this paper.AcknowledgementsThis research was funded by a Standard Research Grant awarded to theauthor by the Social Sciences and Humanities Research Council of Canada(2006–2011). At the time of the research, the author was supported by aSenior Scholar career award (2007–2012) from the Michael Smith Foundationfor Health Research.Received: 3 April 2012 Accepted: 3 October 2012Published: 12 October 2012References1. Public Health Agency of Canada: Report from the Canadian Chronic DiseaseSurveillance System: Hypertension in Canada, 2010. Ottawa, Ontario: Centrefor Chronic Disease Prevention and Control; 2010.2. National Center for Health Statistics: Health, United States, 2011 with SpecialFeature on Socioeconomic Status and Health. MD: Hyattsville; 2012.3. Williams DR, Neighbors H: Racism, discrimination and hypertension:evidence and needed research. Ethn Dis 2001, S11:800–816.4. Mensah GA, Mokdad AH, Ford ES, Greenlund KJ, Croft JB: State ofdisparities in cardiovascular health in the United States. Circulation 2005,111:1233–1241.5. Williams DR, Collins C: US socioeconomic and racial differences in health.Annual Review of Sociology 1995, 21:349–386.6. Lillie-Blanton M, Parsons PE, Gayle H, Dievler A: Racial differences in health:not just Black and White, but shades of gray. Annu Rev Public Health 1996,17:411–448.7. McKetney E, Ragland D: John Henryism, education, and blood pressure inyoung adults: the CARDIA study. Am J Epidemiol 1996, 143:787–791.8. Levenstein S, Smith MW, Kaplan GA: Psychosocial predictors ofhypertension in men and women. Arch Intern Med 2001, 161:1341–1346.9. Brondolo E, Rieppi R, Kelly KP, Gerin W: Perceived racism and bloodpressure: a review of the literature and conceptual and methodologicalcritique. Ann Behav Med 2003, 25:55–65.10. Krieger N, Sidney S: Racial discrimination and blood pressure: the CARDIAstudy of young black and white adults. Am J Public Health 1996,86:1370–1378.11. James SA: John Henryism and the health of African Americans. Cult MedPsychiatry 1994, 18:163–182.12. Chae DH, Lincoln KD, Adler NE, Syme SL: Do experiences of racialdiscrimination predict cardiovascular disease among African Americanmen? The moderating role of internalized negative racial groupattitudes. Soc Sci Med 2010, 71:1182–1188.13. Wu Z, Noh S, Kaspar V, Schimmele CM: Race, ethnicity, and depression inCanadian society. J Health Soc Behav 2003, 44:426–441.14. Wu Z, Schimmele CM: Racial/ethnic variation in functional andself-reported health. Am J Public Health 2005, 95:710–716.15. Veenstra G: Racialized identity and health in Canada: results from anationally representative survey. Soc Sci Med 2009, 69:538–542.16. Veenstra G: Mismatched racial identities, colourism, and health inToronto and Vancouver. Soc Sci Med 2011, 73:1152–1162.17. Veenstra G: Race, gender, class, and sexual orientation: intersecting axesof inequality and self-rated health in Canada. International Journal forEquity in Health 2011, 10:1–11.18. Chiu M, Austin PC, Manuel DG, Tu JV: Comparison of cardiovascular riskprofiles among ethnic groups using population health surveys between1996 and 2007. Can Med Assoc J 2010, 182:E301–E310.19. Liu R, So L, Mohan S, Khan N, King K, Quan H: Cardiovascular risk factors inethnic populations within Canada: Results from national cross-sectionsurveys. Open Medicine 2010, 4:E143–E153.20. Black J, Veenstra G: A cross-cultural quantitative approach tointersectionality and health: using interactions between gender, race,class and neighbourhood to predict self-rated health in Toronto andNew York City. In Health Inequities in Canada: Intersectional Frameworks andVeenstra International Journal for Equity in Health 2012, 11:58 Page 9 of 10http://www.equityhealthj.com/content/11/1/58Practices. Edited by Hankivsky O. Vancouver: University of British ColumbiaPress; 2011:71–91.21. Roth W: Racial mismatch: the divergence between form and function indata for monitoring racial discrimination of Hispanics. Social ScienceQuarterly 2010, 91:1288–1311.22. Williams DR, Yu Y, Jackson JS, Anderson NB: Racial differences in physicaland mental health: Socio-economic status, stress and discrimination.J Health Psychol 1997, 2:335–351.23. Gee GC, Spencer MS, Chen J, Takeuchi D: A nationwide study ofdiscrimination and chronic health conditions among Asian Americans.Am J Public Health 2007, 97:1275–1282.24. Puhl RM, Andreyeva T, Brownell K: Perceptions of weight discrimination:prevalence and comparison to race and gender discrimination inAmerica. Int J Obes 2008, 32:992–1000.25. Roberts CB, Vines AI, Kaufman JS, James SA: Cross-sectional associationbetween perceived discrimination and hypertension in African-Americanmen and women. The Pitt County Study. Am J Epidemiol 2008,167:624–632.26. Pendakur K, Pendakur R: The colour of money: earnings differentialsamong ethnic groups in Canada. Canadian Journal of Economics 1998,31:518–548.27. Skuterud M: The visible minority earnings gap across generations ofCanadians. Canadian Journal of Economics 2010, 43:860–881.28. Reitz JG, Banerjee R: Racial inequality, social cohesion, and policy issues inCanada. In Social Inequality in Canada: Patterns, Pathways, and Policies. 5thedition. Edited by Grabb E, Guppy N. Toronto: Pearson Education Canada;2009:273–294.29. Krieger N: Discrimination and health. In Social Epidemiology. Edited byBerkman LF, Kawachi I. Oxford: Oxford University Press; 2000:36–75.30. Kandula NR, Lauderdale DS, Baker DW: Differences in self-reported healthamong Asians, Latinos, and non-Hispanic Whites: The role of languageand nativity. Ann Epidemiol 2007, 17:191–198.doi:10.1186/1475-9276-11-58Cite this article as: Veenstra: Expressed racial identity and hypertensionin a telephone survey sample from Toronto and Vancouver, Canada: dosocioeconomic status, perceived discrimination and psychosocial stressexplain the relatively high risk of hypertension for Black Canadians?International Journal for Equity in Health 2012 11:58.Submit your next manuscript to BioMed Centraland take full advantage of: • Convenient online submission• Thorough peer review• No space constraints or color figure charges• Immediate publication on acceptance• Inclusion in PubMed, CAS, Scopus and Google Scholar• Research which is freely available for redistributionSubmit your manuscript at www.biomedcentral.com/submitVeenstra International Journal for Equity in Health 2012, 11:58 Page 10 of 10http://www.equityhealthj.com/content/11/1/58

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