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First published online on March 30, 2007
Chest, doi:10.1378/chest.06-1968
doi:10.1378/chest.06-1968
(Chest. 2007; 131:1323-1330)
© 2007 American College of Chest Physicians
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Asthma in American Indian Adults*

The Strong Heart Study

Anne E. Dixon, MD, FCCP; Fawn Yeh, MPH, PhD; Thomas K. Welty, MD, MPH; Everett R. Rhoades, MD; Elisa T. Lee, PhD; Barbara V. Howard, PhD; Paul L. Enright, MD; for the Strong Heart Study Research Group

* From the University of Vermont College of Medicine (Dr. Dixon), Burlington, VT; Center for American Indian Health Research (Dr. Yeh), College of Public Health, University of Oklahoma Health Sciences Center, Oklahoma City, OK; Strong Heart Study (Dr. Welty), Missouri Breaks Research, Timber Lake, SD; College of Public Health (Dr. Rhoades), University of Oklahoma, Oklahoma City, OK; Center for American Indian Health Research (Dr. Lee), College of Public Health, University of Oklahoma Health Sciences Center, Oklahoma City, OK; MedStar Research Institute (Dr. Howard), Hyattsville, MD; and University of Arizona (Dr. Enright), Tuscon, AZ.

Correspondence to: Anne E. Dixon, MD, University of Vermont College of Medicine, Patrick 204, 111 Colchester Ave, Burlington, VT 05401; e-mail: anne.dixon{at}vtmednet.org

Abstract

Background: Despite growing recognition that asthma is an important cause of morbidity among American Indians, there has been no systematic study of this disease in older adults who are likely to be at high risk of complications related to asthma. Characterization of the impact of asthma among American Indian adults is necessary in order to design appropriate clinical and preventive measures.

Methods: A sample of participants in the third examination of the Strong Heart Study, a multicenter, population-based, prospective study of cardiovascular disease in American Indians, completed a standardized respiratory questionnaire, performed spirometry, and underwent allergen skin testing. Participants were ≥ 50 years old.

Results: Of 3,197 participants in the third examination, 6.3% had physician-diagnosed asthma and 4.3% had probable asthma. Women had a higher prevalence of physician-diagnosed asthma than men (8.2% vs 3.2%). Of the 435 participants reported in the asthma substudy, morbidity related to asthma was high: among those with physician-diagnosed asthma: 97% reported trouble breathing and 52% had severe persistent disease. The mean FEV1 in those with physician-diagnosed asthma was 61.3% of predicted, and 67.2% reported a history of emergency department visits and/or hospitalizations in the last year, yet only 3% were receiving regular inhaled corticosteroids.

Conclusions: The prevalence of asthma among older American Indians residing in three separate geographic areas of the United States was similar to rates in other ethnic groups. Asthma was associated with low lung function, significant morbidity and health-care utilization, yet medications for pulmonary disease were underutilized by this population.

Key Words: American Indian • Arizona • asthma • epidemiology • Native American • North Dakota • Oklahoma • South Dakota • spirometry

American Indians have increased morbidity and mortality related to diseases such as cardiovascular disease, diabetes, and cancer.123 Less is known about morbidity and mortality related to respiratory diseases. Asthma and chronic respiratory symptoms are significant causes of morbidity in American Indian, Alaska Native, and Canadian First Nation children.456 In adults, Canadian Aboriginals had increased asthma morbidity (emergency department and office visits) compared to non-Aboriginals.7 However, Singleton et al8 recently reported that asthma hospitalizations were slightly lower for American Indians compared with the general US population.

In the general population, there is a growing awareness that the elderly have significant morbidity related to asthma9; among adults, asthma hospitalization rates are highest in the elderly.8 Asthma has not previously been studied in elderly American Indians despite the fact that this population may have unique socioeconomic and cultural factors affecting the care of their asthma.10

To determine if asthma is a significant problem in older American Indians, and to investigate whether American Indians have adequate management of their disease, we studied the impact of asthma in a cohort of older American Indians; the participants were a subset of a those taking part in a longitudinal cohort study of cardiovascular disease in American Indians, the Strong Heart Study (SHS).

Materials and Methods

Recruitment
The SHS is a multicenter, population-based, prospective study of cardiovascular disease and its risk factors among American Indian adults who are members of the Pima/Maricopa and Papago tribes of central Arizona, seven tribes in southwestern Oklahoma (living near Anandarko, Lawton, and Carnegie), and selected Nakota and Lakota tribes in North Dakota and South Dakota (near Fort Totten, Pine Ridge, and Eagle Butte).11 This substudy was performed during the third examination of the SHS between 1996 and 1999.3 Participants were ≥ 50 years old during the third examination. Details of eligibility and enrollment have been published elsewhere.3 The research protocol was approved by the institutional review boards at each center and the appropriate Indian Health Service, and by the 13 participating tribes. Informed consent was obtained from all participants.

Participants were eligible for the asthma substudy if they reported any of the following: asthma, attacks of wheezing with shortness of breath, diagnosis of asthma since the second examination, shortness of breath with wheezing at night, attacks of wheezing with shortness of breath during the last 12 months, or use of any asthma inhalers during the last 12 months. The procedures described below were performed only on participants in this substudy.

Interview
The interview included a subset of questions from the standardized American Thoracic Society-Division of Lung Diseases and International Union Against Tuberculosis and Lung Disease questionnaires.12 Participants were asked about comorbidities, health-care utilization, and pulmonary medications received during the previous 12 months. Use of medication was ascertained from patient self-report.

Spirometry
Spirometry was performed by centrally trained and certified nurses and technicians.1314 Normal reference values are those for the SHS population.13

Allergen Skin Testing
Skin-prick testing followed standardized techniques for epidemiologic studies.15 Antigens included three grasses, four weeds, four trees, four molds, two mites, cat, dog, cockroach, horse, and cattle. Participants were considered atopic if the panel was valid and any of the allergen results were positive (size of wheal 3 mm larger than negative glycerin control at 15 min).

Definitions
Participants with a > 20 pack-year smoking history or congestive heart failure (ejection fraction on echocardiogram < 40% or history of congestive heart failure if an echocardiogram was not available) were excluded from the asthma categories. Cases were categorized as "physician diagnosed," "probable," "former," or "no" asthma according to the algorithm in Figure 1 .


Figure 1
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  		Figure 1. Details of inclusion and asthma classification of participants in the asthma substudy of the third examination of the SHS.

 
Disease Severity
Disease severity was classified according to National Asthma Education and Prevention Program recommendations.16

Statistical Analysis
{chi}2 tests were used to examine the associations of asthma status (none, former, probable, and physician diagnosed) with a number of categorical variables; exact corrections were used for cells with fewer than five observations. These categorical variables included demographic characteristics, asthma symptoms, severity indicators, and medication use. Associations of asthma status with continuous variables were assessed using analysis of variance methods. We performed univariate and multiple regression analysis to determine factors that were associated with low lung function and health-care utilization. Factors considered for inclusion in the models included smoking (pack-year and current), gender, body mass index, diabetes, poverty, hay fever, sinusitis, and asthma medications. Given the overall low lung function in this population, we defined low lung function as FEV1 < 60% of predicted for the purposes of these analyses. All analyses were performed using statistical software (SAS version 8.0; SAS Institute; Cary, NC).

Results

Characteristics of Participants in the Third Examination of the SHS
A total of 3,197 participants took part in the third examination: 6.3% had physician-diagnosed asthma, and 4% had probable asthma. The prevalence of physician-diagnosed asthma and probable asthma in the third examination was higher in women than men (8.2% of women vs 3.2% of men for physician-diagnosed asthma and 5.2% vs 2.9% for probable asthma). Selected characteristics of the entire cohort are shown in Table 1.


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  		Table 1. Characteristics of All SHS Participants Attending the Third Examination (1996–1999) Compared to the Subset in the Asthma Substudy*

 
Characteristics of Participants in the Asthma Substudy
Compared to the entire cohort, 77% of those with physician-diagnosed asthma (n = 147) and 59% of those with probable asthma (n = 77) chose to participate in this substudy: 334 subjects (77%) were female, and 101 subjects (23%) were male (Table 1). The proportion of those with a family income < $5,000 was slightly higher in the substudy.

Respiratory Symptoms in the Asthma Substudy
Morbidity related to breathing problems was high: 97% of those with physician-diagnosed asthma and 83% with probable asthma reported difficulty breathing (Table 2 ). Of those participants with physician-diagnosed disease, 72% reported that their breathing was worse during a particular season. Participants with physician-diagnosed asthma reported very high prevalence of shortness of breath with physical activity and being woken by breathing difficulties.


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  		Table 2. Prevalence of Respiratory Symptoms*

 
Disease Severity
Severe persistent disease was found in 52% of those with physician-diagnosed asthma, 21% with probable asthma, and 29% of those with former asthma (although the latter denied having current asthma) [Table 3 ]. Of those with physician-diagnosed asthma, there was a slightly higher prevalence of severe disease in the Dakotas and Oklahoma.


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  		Table 3. Asthma Severity*

 
Pulmonary Function and Atopy
Mean FEV1 percentage of predicted values were much lower in those with physician-diagnosed asthma (61.3%) compared to those with no asthma (86.6%) [Table 4 ]. Lung function was also markedly impaired in those with former asthma (mean FEV1, 56.5% of predicted). Multivariate regression analysis showed that hypertension, atopy, and asthma medication were significantly related to low FEV1 (Table 5 ).


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  		Table 4. Association of Asthma Status With Pulmonary Function and Atopy*

 

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  		Table 5. Adjusted Odds Ratios (95% Confidence Intervals) for Low FEV1 (< 60% of Predicted)

 
A significantly higher proportion of participants with physician-diagnosed asthma were atopic than those without asthma (50% vs 38%). This was most notable for dust mite (Dermatophagoides farinae), with 22% of those with physician-diagnosed asthma who were skin test positive, and 11% of those without asthma (p = 0.015).

Pulmonary Medication
Daily use of controller medication among participants with physician-diagnosed asthma was low, with only 3% receiving daily inhaled corticosteroids; 58% were receiving short-acting ß-agonists on a scheduled or as-needed basis. Asthma medication usage was also low in those with probable asthma (Table 6 ).


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  		Table 6. Asthma Medications Used by Subjects With Definite Asthma and Probable Asthma*

 
Health-Care Utilization
Of patients with physician-diagnosed asthma, 67% reported an emergency department visit or hospitalization for asthma or breathing problems in the last 12 months. They reported an average of 2.8 visits (SD 5.8) to their primary care provider (PCP) for their asthma in the last 12 months. Univariate and multivariate analysis showed that hypertension, asthma medication use, and poverty were associated with emergency department visits or hospitalizations; hypertension and poverty were actually associated with a decreased risk of this type of health-care utilization (Table 7 ). Among those with physician-diagnosed asthma, 22% thought their asthma management was very good or excellent, and another 50% reported that they believed they had adequate information (Table 8 ).


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  		Table 7. Adjusted Odds Ratios for Emergency Department Visits and Hospitalizations

 

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  		Table 8. Health-Care Utilization by Participants With Physician-Diagnosed Asthma*

 
Discussion

This study shows that asthma is a common, often severe problem among older American Indian adults. Asthma causes marked morbidity in terms of symptoms and health-care utilization, yet use of controller medications was uncommon.

Historically, a low prevalence of asthma was reported in the American Indian population; rather respiratory infections, such as pneumonia and tuberculosis, were a more significant source of morbidity and mortality.171819 More recently, asthma prevalence was reported to be similar in Alaska Natives and non-Native Medicaid recipients < 20 years old, but there are few data addressing prevalence of asthma in older adults in the lower 48 states.6 The 6% prevalence of physician-diagnosed asthma is slightly higher than that reported for the US population as a whole > 50 years old.2021 However underdiagnosis of asthma in our study may have been significant; 4% of participants of participants in the third examination of the SHS had probable but previously undiagnosed asthma. Gessner and Neeno6 also reported underdiagnosis of asthma in the Alaska Native population, as areas with resident pediatricians and previous participation in asthma research reported a fivefold to 11-fold higher prevalence of asthma than other areas. Underdiagnosis of asthma is an important issue that also has been identified in other populations of older non-American Indian adults: a previous US study22 found 4% of the elderly population had undiagnosed asthma.

Participants in this study had fairly severe disease. Certainly our inclusion criteria would have selected symptomatic individuals, but the data still point to substantial morbidity related to asthma. When we applied asthma severity criteria to those with "former" asthma, we found they had significant disease, suggesting they may still have significant asthma-related morbidity. Studies of asthma in older populations have reported similar findings: a cross-sectional study23 in Baltimore reported that two thirds of their population had severe or moderate persistent disease, and the Cardiovascular Health Study22 found that 58% of their population with asthma had severe or moderate persistent disease.

The mean FEV1 in those with physician-diagnosed asthma was only 61% of predicted; low FEV1 has been reported for similar age groups with asthma.222425 Participants with former asthma had low lung function measured by FEV1; this may reflect loss of lung function with long-standing disease.26 Atopy and hypertension were associated with low lung function in this population. Atopy has also been associated with accelerated loss of lung function in other populations.27 Low lung function has previously been associated with hypertension28; in fact, low FVC has been reported as a risk factor for the development of hypertension.29

Participants had severe disease as measured by health care utilization. Another recent study found that asthma-related hospitalizations for American Indians were slightly lower than that for the general population8; Singleton et al8 reported higher hospitalization rates in the Southwest compared with the Northern Plains and Oklahoma regions. This contrasts with our findings in which participants from Arizona reported fewer emergency department visits, fewer PCP visits, and similar rates of hospitalization/emergency department visits. Singleton et al8 determined hospitalization rates from an Indian Health Service inpatient data set; the higher rates of utilization in our study may represent differences between self-report and diagnostic coding, which may also differ in different regions. Not all participants responded to our question regarding emergency department visits or PCP visits, and so it is possible we are slightly overestimating per patient visits in our population; nevertheless, there appears to be substantial morbidity related to asthma in a large number of individuals. Other studies in similar populations, such as the Aboriginal population in Canada, have shown a similar high rate of health-care utilization in terms of emergency department visits; in fact, health-care utilization for emergency department visits was higher for Aboriginals than it was for a matched non-Aboriginal low-income population.7 We found that poverty and hypertension were associated with decreased emergency department visits/hospitalizations; this was unexpected and will require further study. Asthma medication use was associated with increased emergency department visits/hospitalizations; we speculate that while patients are using rescue inhalers for their symptoms, their asthma could be better managed with the use of more controller medication.

The infrequent use of controller medication was noteworthy. We do not have information regarding prescriptions or pharmacy records to confirm our observations. This study was not designed to evaluate the level of health care for American Indians with asthma and do not permit firm conclusions relating to its overall management among this population – moreover, the study was performed between 1996 and 1999, and may not reflect current practice. The data are self-reported, specific locus of care was not obtained, and patient compliance was not evaluated, but our finding of under utilization of controller therapy is comparable to reports in other populations which have found that only a minority of patients hospitalized for asthma exacerbations subsequently receive inhaled corticosteroids.303132 In our study, the majority of participants (58%) were receiving inhaled rescue therapy. However, the low self-reported use of controller medications suggests that further examination of the management of asthma among older American Indians would provide valuable information relating to optimum regimens, including various barriers to care. Increasing the use of inhaled corticosteroids in this population could have a significant impact on morbidity; in a study6 of Alaska Native children, yearly hospitalization risk decreased (from 9.3 to 6.8%; p = 0.02) with increased use of inhaled corticosteroids.

There are limitations to the data presented. Our data pertain only to an elderly population; however, the elderly represent an increasing proportion of the asthmatic population, which have been poorly studied in the past.30 Participants were eligible for this study if they had respiratory symptoms, and so the burden of respiratory symptoms reported in our "no asthma" group may reflect other respiratory diseases (although COPD should not be significant because we excluded participants with a > 20 pack-year smoking history). This was not a population control group; however, this design allowed us to separate risk factors that were specifically associated with asthma, as opposed to nonasthmatic pulmonary processes. Another potential limitation is that we did not have equal representation by gender. This may reflect the fact it was not a random sample, but participants were selected to have asthma and respiratory symptoms, and asthma is known to more common in adult women than men.33 All interviews were conducted in English; in the experience of the SHS, language has not been an issue, even in this elderly population.

In summary, the present study describes the prevalence, epidemiology, and major clinical manifestations of self-reported asthma among a large group of older American Indians residing in three separate locations. Our data suggest that further delineation of asthma and related conditions among older American Indians, along with attention to clinical management, are warranted.

Acknowledgements

Research specialist Pam Boyer-Pfersdorf wrote the manuals of operation, purchased the supplies, taught the nurses and technicians, and reviewed the quality of spirometry and allergen skin tests. We also thank the SHS technicians and nurses for enthusiastically working with the study participants, including Dr. Tauqeer Ali, Betty Jarvis, Martha Stoddart, Beverly Price, and Marcia O’Leary. We appreciate the Indian Health Service for the use of their clinics, and the wonderful support and cooperation of the following Indian tribes and communities: Ak-Chin Papago/Pima, Apache, Caddo, Cheyenne River Sioux, Comanche, DE, Spirit Lake, Fort Sill Apache, Gila River and Salt River Pima/Maricopa, Kiowa, Oglala Sioux, and Wichita. We also thank Charles G. Irvin, PhD, for his helpful comments.

Footnotes

Abbreviations: PCP = primary care provider; SHS = Strong Heart Study

The opinions expressed in this article are those of the authors and do not necessarily reflect the views of the Indian Health Service.

Supported by National Heart, Lung, and Blood Institute contracts U01-HL41642, HL41652, and HL41654, and grant K23 RR019965.

The authors have no financial or other potential conflicts of interest to disclose.

Received for publication August 8, 2006. Accepted for publication January 31, 2007.

References

  1. Harwell, TS, Miller, SH, Lemons, DL, et al (2006) Cancer incidence in Montana: rates for American Indians exceed those for whites. Am J Prev Med 30,493-497[CrossRef][ISI][Medline]
  2. Howard, BV, Lee, ET, Cowan, LD, et al Rising tide of cardiovascular disease in American Indians: the Strong Heart Study. Circulation 1999;99,2389-2395[Abstract/Free Full Text]
  3. Lee, ET, Howard, BV, Savage, PJ, et al Diabetes and impaired glucose tolerance in three American Indian populations aged 45–74 years: the Strong Heart Study. Diabetes Care 1995;18,599-610[Abstract]
  4. Sin, DD, Sharpe, HM, Cowie, RL, et al Spirometric findings among school-aged First Nations children on a reserve: a pilot study. Can Respir J 2004;11,45-48[Medline]
  5. Liu, LL, Stout, JW, Sullivan, M, et al Asthma and bronchiolitis hospitalizations among American Indian children. Arch Pediatr Adolesc Med 2000;154,991-996[Abstract/Free Full Text]
  6. Gessner, BD, Neeno, T Trends in asthma prevalence, hospitalization risk, and inhaled corticosteroid use among Alaska native and nonnative Medicaid recipients younger than 20 years. Ann Allergy Asthma Immunol 2005;94,372-379[ISI][Medline]
  7. Sin, DD, Wells, H, Svenson, LW, et al Asthma and COPD among aboriginals in Alberta, Canada. Chest 2002;121,1841-1846[Medline]
  8. Singleton, RJ, Holman, RC, Cobb, N, et al Asthma hospitalizations among American Indian and Alaska Native people and for the general US population. Chest 2006;130,1554-1562[Medline]
  9. Enright, P The diagnosis of asthma in older patients. Exp Lung Res 2005;31(Suppl 1),15-21
  10. Van Sickle, D, Morgan, F, Wright, AL Qualitative study of the use of traditional healing by asthmatic Navajo families. Am Indian Alaska Native Ment Health Res 2003;11,1-18
  11. Lee, ET, Welty, TK, Fabsitz, R, et al The Strong Heart Study: a study of cardiovascular disease in American Indians; design and methods. Am J Epidemiol 1990;132,1141-1155[Abstract/Free Full Text]
  12. Burney, PG, Chinn, S, Britton, JR, et al What symptoms predict the bronchial response to histamine? Evaluation in a community survey of the bronchial symptoms questionnaire (1984) of the International Union Against Tuberculosis and Lung Disease. Int J Epidemiol 1989;18,165-173[Abstract/Free Full Text]
  13. Marion, MS, Leonardson, GR, Rhoades, ER, et al Spirometry reference values for American Indian adults: results from the Strong Heart Study. Chest 2001;120,489-495[Medline]
  14. American Thoracic Society.. Standardization of spirometry, 1994 update. Am J Respir Crit Care Med 1995;152,1107-1136[ISI][Medline]
  15. Haahtela, T, Bjorksten, F, Heiskala, M, et al Skin prick test reactivity to common allergens in Finnish adolescents. Allergy 1980;35,425-431[ISI][Medline]
  16. National Institute of Health, National Heart, Lung, and Blood Institute.. Guidelines for the diagnosis and management of asthma: expert panel report 2. 1997 National Institutes of Health. Bethesda, MD: publication No. 97–4051
  17. Slocum, R, Thompson, F, Chavez, C Rarity of asthma among Cheyenne Indians [letter].Ann Allergy 1975;34,201-202[ISI][Medline]
  18. Houston, CS, Weiler, RL, MacKay, RW Native children’s lung. J Can Assoc Radiol 1979;30,218-222[ISI][Medline]
  19. Rhoades, ER The major respiratory diseases of American Indians. Am Rev Respir Dis 1990;141,595-600[ISI][Medline]
  20. Mannino, DM, Homa, DM, Akinbami, LJ, et al Surveillance for asthma–United States, 1980–1999. MMWR Surveill Summ 2002;51,1-13[Medline]
  21. Arif, AA, Delclos, GL, Lee, ES, et al Prevalence and risk factors of asthma and wheezing among US adults: an analysis of the NHANES III data. Eur Respir J 2003;21,827-833[Abstract/Free Full Text]
  22. Enright, PL, McClelland, RL, Newman, AB, et al Underdiagnosis and undertreatment of asthma in the elderly: cardiovascular Health Study Research Group. Chest 1999;116,603-613[CrossRef][Medline]
  23. Huss, K, Naumann, PL, Mason, PJ, et al Asthma severity, atopic status, allergen exposure and quality of life in elderly persons. Ann Allergy Asthma Immunol 2001;86,524-530[ISI][Medline]
  24. Bailey, WC, Richards, JM, Jr, Brooks, CM, et al Features of asthma in older adults. J Asthma 1992;29,21-28[ISI][Medline]
  25. Bauer, BA, Reed, CE, Yunginger, JW, et al Incidence and outcomes of asthma in the elderly: a population-based study in Rochester, Minnesota. Chest 1997;111,303-310[CrossRef][ISI][Medline]
  26. Lange, P, Parner, J, Vestbo, J, et al A 15-year follow-up study of ventilatory function in adults with asthma. N Engl J Med 1998;339,1194-1200[Abstract/Free Full Text]
  27. Tracey, M, Villar, A, Dow, L, et al The influence of increased bronchial responsiveness, atopy, and serum IgE on decline in FEV1: a longitudinal study in the elderly. Am J Respir Crit Care Med 1995;151,656-662[Abstract]
  28. Enright, PL, Kronmal, RA, Smith, VE, et al Reduced vital capacity in elderly persons with hypertension, coronary heart disease, or left ventricular hypertrophy: the Cardiovascular Health Study. Chest 1995;107,28-35[Medline]
  29. Engstrom, G, Wollmer, P, Valind, S, et al Blood pressure increase between 55 and 68 years of age is inversely related to lung function: longitudinal results from the cohort study "Men born in 1914." J Hypertens 2001;19,1203-1208[CrossRef][ISI][Medline]
  30. Braman, SS Asthma in the elderly. Clin Geriatr Med 2003;19,57-75[CrossRef][ISI][Medline]
  31. Sin, DD, Tu, JV Underuse of inhaled steroid therapy in elderly patients with asthma. Chest 2001;119,720-725[Medline]
  32. Hartert, TV, Togias, A, Mellen, BG, et al Underutilization of controller and rescue medications among older adults with asthma requiring hospital care. J Am Geriatr Soc 2000;48,651-657[ISI][Medline]
  33. Rose, D, Mannino, DM, Leaderer, BP Asthma prevalence among US adults, 1998–2000: role of Puerto Rican ethnicity and behavioral and geographic factors. Am J Public Health 2006;96,880-888[Abstract/Free Full Text]




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