Guest editorial

Inner-city disadvantaged populations and asthmaprevalence, morbidity, and mortality

Despite the improved knowledge ofthe pathophysiology and natural his-tory of asthma, the prevalence of thedisease is still rising worldwide.1 Fur-ther, although the increased mortalityrate of asthma seen in the past decadehas stimulated much discussion and re-search, there continues to be contro-versy concerning which factor(s) con-tributes to the greater prevalence andmortality of the disease in relationshipto race and socioeconomic status.There are several putative factors

which can be implicated to explain thisincrease in asthma morbidity and mor-tality in relationship to disadvantagedpatients with asthma, which includethe following: genetic predisposition tothe development of severe asthma, ex-posure to cockroach allergen, exposureto dust mite early in life, exposure totobacco smoke, lack of asthma educa-tion and access to support groups, in-adequate management by primary carephysicians, lack of access to asthmaspecialists, and lack of appreciation ofthe role of early intervention and con-trol of bronchial inflammation.2A recent study by Ray et al3 sug-

gested that the asthma hospitalizationrate for African Americans was fourtimes higher than other populations,after stratification by age, income, andurbanicity, and that this was indepen-dent of income. Regardless of race,poverty was the single most importantrisk factor for asthma hospitalization.Patients with a high school educa-

tion or less had more severe asthma,possibly correlating to socioeconomicstatus.4 Passive tobacco smoke expo-sure from parents resulted in increasedairway hyperresponsiveness in theirchildren.5 Also, it has been shown thatthe risk of developing asthma was 2.5

times higher with mothers whosmoked 10 or more cigarettes per day.6An epidemiologic study comparing

the severity of childhood asthma withsocioeconomic status revealed theprevalence of severe asthma to be sig-nificantly higher in the low as com-pared with the high socioeconomicgroup.7 The study by Gibson et al8evaluating the efficacy of asthma edu-cation programs in asthmatics fromlow socioeconomic status, revealedthat asthma knowledge played a bene-ficial role in these patients. Further,socioeconomic deprivation was foundto be an important associated factor inasthmatics hospitalized for exacerba-tion of bronchial asthma.9The study by Goodman et al10

showed that the trends in pediatricasthma hospitalization rates were notnecessarily parallel nationally. Amulti-variated analysis (controllingage, sex, race/ethnicity, income, andmetropolitan status) revealed that NewYork asthma hospitalization rates in-creased 3.8% per annum, whereas inNew Hampshire, rates decreased 5.8%.Maine and Vermont rates did notchange. This was interpreted to meanthat although selected geographicasthma populations needed specializedmedical intervention to improveasthma outcome, this was not uni-formly seen on a national scale. In EastHarlem, for example, examination ofasthma deaths and near-death cases re-vealed that these patients were fromlow socioeconomic status AfricanAmerican and Hispanic populations.11Low socioeconomic status and an in-crease in asthma prevalence could alsobe explained by exposure to high con-centrations of indoor environmental al-lergens, such as dust mite (Der p 1, Der

f 1) induced-sensitization, and dust ex-posure is now considered a dominantrisk factor for asthma.12 Recently, therole of cockroach allergens (Bla g 1and Bla g 2) has been identified asanother major environmental allergen.African American race and low socio-economic status are both independent,significant risk factors for cockroachallergen sensitization in children withatopic asthma. Cockroach allergen isdetectable throughout the house, in-cluding the bedroom environment.13Cockroach allergens (Bla g 1 and Bla g2) are in very high quantities in house-holds of low socioeconomic statuspopulation.14 This allergen poses animportant problem for inner-city chil-dren with asthma.15More recently, as a result of re-

search supported by the National Co-operative Inner-City Asthma Study(NCICAS) of the National Instituteof Allergy and Infectious Diseases(NIAID) of the National Institutes ofHealth (NIH), several important find-ings have been made with reference todisadvantaged inner-city populationsand asthma. The report by Rosenst-reich et al16 has provided further evi-dence for the role of cockroach in theinduction of immediate hypersensitiv-ity to these allergens and asthma.These investigators have demonstratedthat the degree of exposure of childrenwith positive skin tests to cockroachallergens, as measured by Bla g 1 indust from their bedrooms, was corre-lated with their risks of hospitaliza-tions.In addition, high morbidity and mor-

tality from bronchial asthma observedin the African American population arerelated to higher exposure and sensiti-zation to cockroach allergens that are

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more prevalent in lower socioeco-nomic status environments. Further,the authors also raised the possibilityof the role of genetic factors contrib-uting to the higher degree of sensitiza-tion, resulting in more severe asthma.17Another contributing factor to mor-

bidity is the higher primary noncom-pliance in patients with asthma, par-ticularly those from disadvantagedpopulations. The primary care physi-cian, therefore, should not only focuson correct technical use of asthmamedication but also should spend moretime educating patients on the need fortreatment. This is particularly relevantfor asthma groups of low socioeco-nomic status and they may requiremore intensive counseling.18–20The presence of domestic pets (ie,

cat and dog) has also been shownto increase the prevalence of asth-ma symptoms.21 Paradoxically, pa-tients allergic to cats were from highsocioeconomic status.22 There are sig-nificant differences between patients’self-management knowledge and asth-matics’ actual behavior in terms of po-tentially lifesaving actions. Socioeco-nomic factors have a powerful anddifferential influence on knowledgeand asthma behavior.23Patients with frequent emergency

room visits revealed lesser knowledgeof asthma control criteria and skills.24Asthma educational programs given tolow socioeconomic status patients re-sulted in reduction of emergency roomvisits and hospitalization, favoringspecific target populations to benefitfrom asthma education programs.25Analysis of ethnic differences in the

prevalence of asthma in children re-vealed that the lifetime prevalence ofasthma was 12% for blacks and 6% forwhites. In this analysis, black andwhite families were similar socioeco-nomically and geographically locatedin the same middle class community.Access to medical care was also simi-lar across the study population, sug-gesting that there are differences inbiologic factors between blacks andwhites. These biologic factors could begenetic and play a role in asthma risk.26

Among the risk factors for asthmat-ics requiring intubation were low so-cioeconomic status, family dysfunc-tion, unemployment, tobacco smokeexposure/use, and language barrier.These parameters may be importantdeterminants of risk for asthma deathsand their recognition may have signif-icant implication as preventative mea-sures.27Some studies have not supported a

causal relationship of race and socio-economic status with asthma. Thestudy by Ones et al28 evaluated thefactors involved in the prevalence ofchildhood asthma in children 6 through12 years of age. The results of thestudy showed that the prevalence ofchildhood asthma was not affected bysocioeconomic status, the heating sys-tem at home, the place of residence,the educational levels of the parents,the number of people living in thehouse, and the annual family income.In contrast, atopic family history, foodallergy, eczema, and frequent otitis andsinusitis were found to be significant inasthma prevalence.A multi-ethnic comparison study in

asthmatics among Puerto Rican His-panics revealed that the increased riskfor asthma in Puerto Rican Hispanicswas not explained by socioeconomicstatus nor by environmental exposureto tobacco smoke. The Hispanic eth-nicity appeared to be a risk factor non-confounded by socioeconomic status.29A study conducted in Canada on so-cioeconomic status and indicators ofasthma in children revealed that un-identified environmental factors con-tributed to increased asthma morbidityin poor children.30In the September issue of the An-

nals, the study by Persky et al31 pro-vided further data to support the rela-tionship of race and socioeconomicstatus with prevalence, severity, andsymptoms of asthma in Chicago schoolchildren. The authors found thatasthma prevalence was higher than the5% to 10% previously reported, withthe highest rates in patients from mi-nority and low socioeconomic groups,and that limitation in access to healthcare could be affecting high rates of

asthma in Chicago. It would have beenhelpful to have had more precise andindividualized data on asthma risk fac-tors such as race, income, and tobaccosmoke, rather than relying solely uponthe ecologic analysis used in the study.It also would have been helpful topresent a review of some of the sub-jects’ medical records to confirm andprovide objective evidence for the di-agnosis of asthma.Collectively, the results of the study

by Persky et al are of particular rele-vance not only to the practicing aller-gists who need to direct their diagnos-tic and therapeutic strategies topatients with asthma from disadvan-taged populations, but also to legisla-tors who need these data to write ap-propriate and relevant legislation, aswell as health insurance organizationsto effectively utilize resources for thebenefit of these patients.

TALAL M NSOULI, MD, FACAAIAssociate Professor of ClinicalPediatrics

Georgetown University School ofMedicine

Director, Watergate Allergy &Asthma Center

Washington, DC

REFERENCES1. Publication No. 95-3659. Global ini-tiative for asthma: global strategy forasthma management and prevention.NIH 1995;9–25.

2. Nsouli TM, Nsouli SM, Scanlon RT,Bellanti JA. Neuroimmunoallergicinflammation: new pathogenetic con-cepts and future perspectives of imme-diate and late allergic reactions, Parts Iand II. Ann Allergy 1988;5:379–89;6:483–493.

3. Ray NF, Thamer M, Fadillioglu B,Gergen PJ. Race, income, urbanicity,and asthma hospitalization inCalifornia: a small area analysis. Chest1998;113:1277–1284.

4. Leidy NK, Coughlin C. Psychometricperformance of the Asthma Quality ofLife Questionnaire in a US sample.Quality Life Res 1998;7:127–134.

5. Stoddard JJ, Miller T. Impact of paren-tal smoking on the prevalence ofwheezing respiratory illness in chil-dren. Am J Epidemiol 1995;141:96–102.

VOLUME 82, JANUARY, 1999 3

6. Martinez FD, Cline M, Burrows B.Increased incidence of asthma in chil-dren of smoking mothers. Pediatrics1992;89:21–26.

7. Mielck A, Reitmeir P, Wjst M. Sever-ity of childhood asthma by socioeco-nomic status. Int J Epidemiol 1996;25:388–393.

8. Gibson PG, Shah S, Mamoon HA.Peer-led asthma education ofadolescents: impact evaluation. J Ado-lescent Health 1998;22:66–72.

9. Watson JP, Cowen P, Lewis RA. Therelationship between asthma admis-sion rates, routes of admission, andsocioeconomic deprivation. Eur RespirJ 1996;9:2087–2093.

10. Goodman DC, Stukel TA, Chang CH.Trends in pediatric asthma hospitaliza-tion rates: regional and socioeconomicdifferences. Pediatrics 1998;101:208–213.

11. Corn B, Hamrung G, Ellis A, et al.Patterns of asthma death and near-death in an inner-city tertiary careteaching hospital. J Asthma 1995;32:405–412.

12. Squillace SP, Sporik RB, Rakes G, etal. Sensitization to dust mites as adominant risk factor for asthma amongadolescents living in central Virginia.Multiple regression analysis of a pop-ulation-based study. Am J Respir CritCare Med 1997;156:1760–1764.

13. Sarpong SB, Hamilton RG, EgglestonPA, Adkinson NF Jr. Socioeconomicstatus and race as risk factors for cock-roach allergen exposure and sensitiza-tion in children with asthma. J AllergyClin Immunol 1996;97:1393–1401.

14. Gelber LE, Seltzer LH, Bouzoukis JK,et al. Sensitization and exposure to in-door allergens as risk factors for

asthma among patients presenting tohospital. Am Rev Respir Dis 1993;147:573–578.

15. Call RS, Smith TF, Morris E, et al.Risk factors for asthma in inner citychildren. J Pediatr 1992;121:862–866.

16. Rosenstreich DL, Eggleston P, KattanM, et al. The role of cockroach allergyand exposure to cockroach allergen incausing morbidity among inner-citychildren with asthma. N Engl J Med1997;336:1356–1363.

17. Togias A, Horowitz E, Joyner D, et al.Evaluating the factors that relate toasthma severity in adolescents. Int Ar-chiv Allergy Immunol 1997;113:87–95.

18. Watts RW, McLennan G, Bassham I,el-Saadi O. Do patients with asthmafill their prescriptions? A primarycompliance study. Australian FamilyPhysician 1997;26:4–6.

19. Taggert VS, Zuckerman AE, Lucas S,et al. Adapting a self-management ed-ucation program for asthma for use inoutpatient clinic. Ann Allergy 1987;58:173.

20. Taggert VS, Zuckerman AE, Sly RM,et al. You can control asthma: evalua-tion of an asthma education programfor hospitalized inner-city children.Patient Educa Council 1991;17:35.

21. Chew FT, Teo J, Quak SH, et al. Pres-ence of domestic pets and respiratorysymptoms in asthmatic children. AnnAcademy Med 1997;26:294–298.

22. Pollart SM, Chapman MD, Fiocco GP,et al. Epidemiology of acute asthma:IgE antibodies to common inhalant al-lergens as risk factors for emergencyroom visits. J Allergy Clin Immunol1989;83:875–882.

23. Kolbe J, Vamos M, Fergusson W, et

al. Differential influences on asthmaself-management knowledge andself-management behavior in acutesevere asthma. Chest 1996;110:1463–1468.

24. Boulet LP, Belanger M, Lajoie P.Characteristics of subjects with a highfrequency of emergency visits forasthma. Am J Emergency Med 1996;14:623–628.

25. de Oliveira MA, Bruno VF, Ballini LS,et al. Evaluation of an educational pro-gram for asthma control in adults. JAsthma 1997;34:395–403.

26. Nelson DA, Johnson CC, Divine GW,et al. Ethnic differences in the preva-lence of asthma in middle class chil-dren. Ann Allergy Asthma Immunol1997;78:21–26.

27. LeSon S, Gershwin ME. Risk factorsfor asthmatic patients requiring intuba-tion. I. Observations in children. JAsthma 1995;32:285–294.

28. Ones U, Sapan N, Somer A, et al.Prevalence of childhood asthma inIstanbul, Turkey. Allergy 1997;52:570–575.

29. Beckett WS, Belanger K, Gent JF, etal. Asthma among Puerto RicanHispanics: a multi-ethnic comparisonstudy of risk factors. Am J Respir CritCare Med 1996;154:894–899.

30. Ernst P, Demissie K, Joseph L, et al.Socioeconomic status and indicators ofasthma in children. Am J Respir CritCare Med 1995;152:570–575.

31. Persky VW, Slezak J, Contreras A, etal. Relationship of race and socioeco-nomic status with prevalence, severityand symptoms of asthma in Chicagoschool children. Ann Allergy AsthmaImmunol 1998;81:266–271.

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