The asthma emergency department visit: treating a crisis in the midst of uncontrolled disease

The asthma emergency department visit: treating a crisis in the midst of uncontrolled disease Richard O. Lenhardt, MD, MPH*; Catherine D. Catrambone, DNSc, RN†; James Walter, MD‡; Michael F. McDermott, MD§; and Kevin B. Weiss, MD¶

Background: Patients with asthma who require emergency department (ED) care are burdened with asthma symptoms, are at risk for hospitalization, and use expensive resources. Objective: To examine whether an ED-based surveillance system that characterized asthma symptoms and care before, during, and after an ED visit enhances our understanding of the natural history of asthma exacerbations. Methods: This cross-sectional follow-up enrolled 225 adult patients who presented to 1 of 6 Illinois EDs for asthma care. Clinical characteristics before ED presentation, care provided in the EDs, and 1-month follow-up status were assessed by self-administered questionnaire, medical record review, and telephone interview, respectively. Results: Persistent asthma symptoms were reported by 85.8% and 84.9% (P ⫽ .37) of patients before their ED visit and follow-up call, respectively. For patients with persistent symptoms before the ED visit and follow-up call, 54.4% and 73.8% (P ⫽ .02) reported using an inhaled corticosteroid, respectively. Inhaled corticosteroids were recommended for 49.4% of discharged patients with persistent symptoms. Relapse rates for return ED visits and return hospitalizations were 26.4% and 9.6%, respectively. Patients had low asthma-specific and general quality-of-life scores at follow-up. Conclusions: Patients with asthma exacerbations most often had uncontrolled asthma before the ED visit that subsequently deteriorated, temporarily improved with ED treatment, and continued as uncontrolled asthma after the ED visit. Although improvements in care were reported 1 month after the ED visit, opportunities for additional improvement were observed. Ann Allergy Asthma Immunol. 2008;100:237–243.

INTRODUCTION Acute asthma can be characterized, in part, as an increase in the frequency or severity of prior asthma symptoms during a short period, usually a week or less. As the severity of the acute asthma event worsens, patients typically present to an emergency department (ED) for asthma care. In the late 1990s in the United States, EDs received approximately 2 million visits for the treatment of asthma exacerbations.1 Such visits reflect an immediate burden on the patient and cost to society and risk for subsequent hospitalization.2,3

Affiliations: * Section of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Rush University Medical Center, Chicago, Illinois; † College of Nursing, Rush University Medical Center, Chicago, Illinois; ‡ Division of Emergency Medicine, University of Chicago, Chicago, Illinois; § Department of Emergency Medicine, John H. Stroger, Jr Hospital of Cook County, Chicago, Illinois; ¶ Institute for Healthcare Studies, Northwestern University Feinberg School of Medicine, Chicago, and Midwest Center for Health Services and Policy Research, Hines VA Hospital, Hines, Illinois. Disclosures: Dr Weiss served on the Scientific Advisory Committee of Merck & Co, Inc. Funding Sources: This study was supported by grant U59CCU520891-01 from the Centers for Disease Control and Prevention. Received for publication June 11, 2007; Received in revised form August 21, 2007; Accepted for publication September 5, 2007.

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National and international guidelines stratify asthma symptom burden into intermittent and persistent categories based on the frequency of daytime and nighttime symptoms.4,5 The clinical course of an ED patient’s asthma symptoms can progress through several different scenarios. Before the ED visit, the patient may have intermittent or persistent symptoms; similarly, after the ED visit, these symptoms may again be intermittent or persistent. Prior studies6 –10 have demonstrated a variable degree of persistent symptoms before and after an asthma exacerbation requiring ED care. To our knowledge, no prior study has evaluated the level of symptom burden and medication use in patients before and after an asthma exacerbation requiring ED care. In addition, more recent guidelines have stressed the concept of control over severity.11 This study uses both concepts. A longitudinal evaluation of patients’ asthma symptoms and medication use before and after an ED visit would help elucidate the clinical course of their asthma control. This would provide a more comprehensive view of the burden of an asthma exacerbation that requires ED care. Such a comprehensive view may suggest the need for enhancing both immediate-care management practices to improve longerterm symptom control and long-term management practices to avoid the necessity of ED visits. The purpose of this study is to characterize the pre-ED, ED, and post-ED illness experience of adults with asthma exacerbations.

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Figure 1. Diagram of Illinois Emergency Department Asthma Collaborative (IEDAC) surveillance instruments in relation to patient emergency department (ED) experience.

Study Population Subjects enrolled in this study were patients who presented to 1 of 6 Illinois EDs from May 19, 2003, to November 5, 2003, and received asthma care. Three of the EDs were part of academic medical centers in Chicago, Illinois. The fourth ED was part of a medical center in suburban Chicago. The final 2 EDs were located within general hospitals in midsized cities greater than 100 km from Chicago. Inclusion criteria were patients who presented to the EDs and received asthma care, had a self-reported physician diagnosis of asthma, and were aged from 18 through 90 years. Patients who had previously completed the survey at a prior ED visit (n ⫽ 18) or had a diagnosis of chronic obstructive pulmonary disease and were older than 65 years (n ⫽ 1) were excluded. All EDs enrolled a convenience sample of 15 subjects per month. The institutional review boards of Northwestern University, Chicago, and all participating hospitals approved this study.

phone-administered survey completed 1 month after the ED visit and contained 54 items. To determine the presence of persistent symptoms, items on the RA survey queried patients on the frequency of daytime and nighttime asthma symptoms and the frequency of use of short-acting ␤-agonist medications. To capture the long-term nature of patients’ asthma, the time window of these questions was the 4 weeks before the worsening of their asthma. Based on national guideline stratification, persistent symptom status was determined by the symptom or shortacting ␤-agonist medication use with the greatest frequency.4 Patients were considered to be using a controller medication if they were using an inhaled corticosteroid, oral corticosteroid, leukotriene modifier, or theophylline.14 Based on guidelines, uncontrolled asthma was defined as the presence of persistent symptoms if the patient was using an asthma medication.4,5 As in the RA survey, the OA survey contained items regarding symptom and short-acting ␤-agonist use frequencies. The response set for these items was identical in both surveys. The questions for these items were similar, with the exception that the RA survey queried patients regarding their symptoms and short-acting ␤-agonist use in the 4 weeks before the onset of their asthma exacerbation, whereas in the OA survey this time window was reduced to the 2 weeks before the OA survey was completed. A different time window was necessary for the OA survey because of the proximity to the ED visit. Except for the time windows, persistent symptom category and uncontrolled asthma status were determined by the same methods in the RA and OA surveys.

Study Instruments Three instruments were used in this study, which included the risk assessment (RA), medical record (MR), and outcome assessment (OA) surveys. The development of these instruments is described in detail elsewhere.12 The RA survey was self-administered and contained 40 items. Race/ethnicity was self-identified according to Census Bureau categories. Race/ ethnicity was evaluated because of its previous association with asthma severity, treatment, and outcomes.13 The MR survey contained 30 items, and the OA survey was a tele-

Data Collection Protocol Trained research assistants (including M.F.M.) who were stationed in the ED screened patients for potential enrollment into the study. Before enrollment, informed and Health Insurance Portability and Accountability Act consents were obtained. While in the ED, patients completed the self-administered RA survey. Within 2 weeks of the patient’s ED discharge, a study team member completed the MR survey. At 3 and 21 days after discharge, patients were mailed a postcard reminding them of the telephone follow-up. One

METHODS Illinois Emergency Department Asthma Collaborative This study is part of the Illinois Emergency Department Asthma Collaborative (IEDAC).12 The principal goals of IEDAC were to develop and test an ED-based asthma surveillance system. The 3 instruments used in this study correspond to patients’ pre-ED, ED, and post-ED experience (Fig 1). This enabled a detailed evaluation of the flow of patients’ experience through different phases of an asthma exacerbation that required ED care. This study reports on results for adult patients before initiation of a quality improvement initiative. Results for children are reported elsewhere.12

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month after discharge, patients completed the OA surveys by telephone interview. Statistical Analysis For completed surveys, the response rate was greater than 95% for all items. Missing data were excluded from the analyses. Proportions are shown for count data. Means and SDs were calculated for continuous data. Inferential testing of paired count data used the McNemar ␹2 or exact test, where appropriate. Inferential testing for continuous data used the t test. Two-tailed P ⱕ .05 was considered statistically significant. Missing data values for health-related quality-of-life scores were imputed. Data management and statistical testing were performed with Stata, version 8.2 (Stata Corp, College Station, Texas). RESULTS Demographic Characteristics at the ED Visit A total of 225 patients were enrolled (Fig 1). As seen in Table 1, their mean age was 39.8 years, 70.0% were women, and 56.5% were black and 34.5% were white. Nearly 58% reported having medical insurance, and 50.3% had at least some high school education. The MR survey found the primary reason recorded for the ED visit was an asthma exacerbation for 89.2% of patients, respiratory complaints consistent with an asthma exacerbation for 5.4%, nonrespiratory conditions for 3.6%, nonspecific respiratory complaints for 0.9%, and medication refill for 0.9%. Nevertheless, all patients were treated for an asthma exacerbation. Clinical Characteristics at ED Visit At presentation, 37.2% of patients reported having 3 or more ED visits (excluding the enrollment visit) in the 12 months

Table 1. Demographic Characteristics of the 225 Patients at the Emergency Department Visit Characteristic Age, y Mean (SD) Range Female Race/ethnicity Black White Other Insurance status Self-report of having any insurance Medical record status of having any insurance Private insurance Medicaid Medicare Highest level of education Some college Some high school Less than high school a

Valuea 39.8 (14.6) 18.1–83.3 70.0 56.5 34.5 9.0 57.6 57.7 25.9 22.3 9.6 42.9 50.3 6.9

Data are given as percentage of patients unless otherwise indicated.

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before the ED visit and 30.2% of patients responded that they were hospitalized in the 12 months before the ED visit. Reported medication use before the ED visit is given in Table 2. Short-acting ␤-agonists were the most frequently used class of medication, followed by inhaled and oral corticosteroids. At the ED visit, 85.8% of patients reported having persistent asthma symptoms before their ED visit (Table 3). Of patients with persistent symptoms, 64.2% reported using a controller medication and 54.4% reported using an inhaled corticosteroid before the ED visit. Only 26.5% of patients with persistent symptoms reported using an inhaled corticosteroid daily. Moderate or severe persistent symptoms were reported in 72.9% of all ED patients. Clinical Management at ED Visit Data were available for all 225 patients from completed MR surveys (Fig 1). As seen in Table 4, an initial peak expiratory flow measurement was documented in 67.0% of medical records. Of the patients, 69.4% were considered to have a condition severe enough to have received more than 1 shortacting ␤-agonist treatment. Systemic corticosteroids were recorded as administered to 75.9% of patients. Of all patients, 83.1% were discharged home. Of those patients who were discharged home and who had persistent symptoms before the ED visit, 49.4% were either newly prescribed or advised to continue taking inhaled corticosteroids. Oral corticosteroids were recorded as prescribed for 73.0% of discharged patients; the mean duration of prescribed oral corticosteroids was 5.6 days. Any asthma education was documented for 67.7% of patients. Ranking of most to least common specific educational element documented was what to do if asthma symptoms worsen, medication action, and observation of correct use of a metereddose inhaler. Outcomes at Follow-up Telephone Survey Of patients, 56.0% were available for follow-up at a median of 32 days. The order of medications reported as used from most to least frequent was similar in the OA survey as in the RA survey (Table 2). Use of any controller medication increased to 80.2% at the follow-up call, use of inhaled corticosteroids increased to 68.0%, and use of oral corticosteroids increased to 36.8%. Use of other medications was not significantly changed at the follow-up call. As for the RA survey, symptom frequency and medication use were evaluated in the OA survey (Table 3). At the follow-up call, the proportion of patients who reported having persistent symptoms was unchanged, at 84.9%. Of patients with persistent symptoms at the follow-up call, 86.9% reported using a controller, whereas 73.8% reported using an inhaled corticosteroid, which were both increased compared with the ED visit. For 58.8% of patients with persistent symptoms, an inhaled corticosteroid was reported to be used daily, which was increased compared with the ED visit. For patients with more significant symptoms, those in the mod-

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Table 2. Reported Medication Use Before the ED Visit and Telephone Follow-up

Medication class

Any medication used Quick-reliever medications Inhaled short-acting ␤-agonistd Epinephrine (Primatene) oral or mist Controller medications Any controller ICS Oral corticosteroid Leukotriene modifier Inhaled long-acting ␤ -agoniste Theophylline

Patients who completed telephone follow-up, % (n ⴝ 126)

All patients at ED visit, % (n ⴝ 225)a

At ED visita

At telephone follow-upb

P value (ED visit vs telephone follow-up)c

89.3

89.7

94.4

.18

86.2 8.9

87.2 8.8

91.3 Not assessed

.36 NA

61.3 51.6 27.9 18.8 9.4 8.6

65.1 53.2 24.2 24.0 11.2 10.5

80.2 68.0 36.8 19.2 11.6 10.4

.001 .007 .02 .15 .73 ⬎.99

Abbreviations: ED, emergency department; ICS, inhaled corticosteroid; NA, data not applicable. Patients using medication in the 4 weeks before the ED visit or in the 4 weeks before the asthma exacerbation for ICSs and short-acting ␤-agonists. b Patients using the medication in the 2 weeks before telephone follow-up. c The McNemar ␹2 test or exact test for paired data was used, where appropriate. d Metaproterenol sulfate (Alupent), albuterol (Ventolin), albuterol (Proventil), or pirbuterol (Maxair). e These medications are appropriately used as controllers only when added to ICSs.14 a

Table 3. Patients With Uncontrolled Asthma and Persistent Symptoms Before the ED Visit and Telephone Follow-up

Symptom and medication use data

Uncontrolled asthmad Persistent symptomsd And used controller And used ICS And used ICS daily Moderate or severe persistent symptomsd And used controller And used ICS And used ICS daily

Patients who completed telephone follow-up, % (n ⴝ 126)

All patients at ED visit, % (n ⴝ 225)a

At ED visita

At telephone follow-upb

P value (ED visit vs telephone follow-up)c

87.6 85.8 64.2 54.4 26.5 72.9 66.5 56.7 29.2

84.1 81.8 70.9 58.2 31.0 66.6 73.8 61.9 35.4

89.1 84.9 86.9 73.8 58.8 69.8 89.8 75.0 62.5

.37 .43 .001 .02 ⬍.001 .50 .01 .14 .009

Abbreviations: ED, emergency department; ICS, inhaled corticosteroid. a Patients with symptoms, short-acting ␤-agonist, and ICS use in the 4 weeks before the asthma exacerbation. For other medications, the time window was the 4 weeks before the ED visit. b Patients with symptom and medication use frequency in the 2 weeks before telephone follow-up. c The McNemar ␹2 or exact test for paired data was used, where appropriate. d As determined by national guidelines.4

erate or severe persistent category, similar proportions reported using inhaled corticosteroids and controller medications as for all patients with persistent symptoms. At the 1-month follow-up call, 26.4% of patients reported having relapsed to an ED visit and 9.6% were hospitalized after discharge from the ED or hospital. Of the patients, 52.4% reported having at least some difficulty with work or daily activities in the 2 weeks before the follow-up call. The

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mean number of days patients reported with asthma symptoms in the 2 weeks before the follow-up call was 7.3. The mean total Mini Asthma Quality of Life Questionnaire score was 4.2, which was worse than that reported for adults seeking ambulatory care for asthma (5.4, P ⬍ .001).15 The mean SF-12 Health Survey (SF-12) physical score was 36.9, and the mean SF-12 mental score was 44.2. These scores were lower than those from a population-based survey of 834

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Table 4. Asthma Assessment, Treatment, Education, and Discharge Practices for Patients in the ED Valuea

Characteristic ED assessment and treatment for all patients (n ⫽ 225) Peak expiratory flow measurements Initial peak flow documented Initial peak flow measurement, L/minb Oxygen saturation documented ⱖ2 ␤-Agonist treatments Systemic corticosteroids received in ED Discharged to home data (n ⫽ 187) Inhaled corticosteroid prescribed or continued For discharged patients For patients with persistent symptoms For patients with moderate or severe persistent symptoms Oral corticosteroid prescribed For discharged patients No. of days medication prescribedb Follow-up advice at discharge Patients advised to follow-up No. of days advised to follow-upb Documentation of asthma education Any asthma education Instructed on what to do if symptoms worsen Instructed on action of medications MDI use observed as part of MDI teaching

67.0 226 (105) 96.9 69.4 75.9 83.1 50.8 49.4 48.9

73.0 5.6 (2.7) 88.7 5.0 (4.6) 67.7 66.1 23.7 4.3

Abbreviations: ED, emergency department; MDI, metered-dose inhaler. a Data are given as percentage of patients unless otherwise indicated. b Data are given as mean (SD).

Table 5. Outcomes for 126 Patients at 1-Month Telephone Follow-up Outcome

Valuea

b

Relapse To ED visit To hospital admission At least some difficulty with work or daily activities in the 2 weeks before the follow-up callb No. of days with asthma symptoms in the 2 weeks before the follow-up call mAQLQ scorec Total of all domains Symptom domain Environment domain Emotion domain Activity domain SF-12 score Physical domain Mental domain

26.4 9.6 52.4

7.3 (5.1)

4.2 (1.4) 4.1 (1.6) 3.7 (1.6) 4.0 (1.9) 4.8 (1.6) 36.9 (10.8) 44.2 (12.5)

Abbreviations: ED, emergency department; mAQLQ, Mini Asthma Quality of Life Questionnaire; SF-12, SF-12 Health Survey. a Data are given as mean (SD) unless otherwise indicated. b Data are given as percentage of patients. c This scale extends from 1 to 7 (1 indicates severe burden of symptoms; and 7, no symptoms).

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adult patients with asthma (46.0 and 51.4, respectively; P ⬍ .001 for both domain scores).16 DISCUSSION Results from this study demonstrate that adults presenting to IEDAC EDs for asthma care had a large burden of disease in the month before the ED visit and this continued 1 month later. These findings were seen for each measure of disease burden, including asthma symptoms and medication use before the ED visit and follow-up call and health-related quality-of-life scores and health care resource use at the 1-month follow-up call. Based on national criteria, 85.8% and 84.9% of patients reported persistent symptoms before the ED visit and follow-up call, respectively. Many patients with more significant moderate or severe persistent symptoms were described as well, occurring in 72.9% of patients before the ED visit and 69.8% of patients before the follow-up call. Of the patients, 27.1% were categorized as having mild symptoms, but nevertheless, had an ED-requiring exacerbation. Although use of these guideline categories has not been validated for acute asthma and successive measurements, we believe most clinicians would find these constructs useful.17 Few other studies have evaluated the presence of persistent symptoms in patients presenting to EDs for immediate care, and none, to our knowledge, have evaluated the presence of persistent symptoms at both the ED visit and follow-up. In pediatric ED patients, 14% to 51% of children were reported to have persistent symptoms before the ED visit.6,7,10 In adult ED patients, 61% to 71% of patients were reported to have moderate or severe persistent asthma 2 to 3 weeks after the ED visit.8,9 The different proportions of patients with persistent symptoms reported may be accounted for by differences in populations, application of guideline criteria, acute asthma severity, sex, or other social demographic factors. Further substantiating the theme that most ED patients had troublesome asthma symptoms resulting in their ED presentation was the finding that 27.9% of patients reported using an oral corticosteroid in the month before their asthma exacerbation. This proportion is similar to the 22.6% reported by Emerman et al.18 The relapse rate to the ED for patients who were initially discharged home was 26.4%, a proportion similar to that reported by others.2,18,19 At the 1-month follow-up call, patients continued to have a significant burden of disease related to asthma, as reflected in quality-of-life scores. Asthma-specific quality of life, as measured by the total Mini Asthma Quality of Life Questionnaire score, was worse than reported for outpatients with asthma.15 General quality of life, as measured by the physical and mental scores of the SF-12, was lower than reported in a population-based survey of patients with asthma.16 Although these instruments have not been formally validated in patients with acute asthma, their use in this context seems to have face validity. A second major finding of this study was that many patients were not using medications as advised by national

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guidelines. National guidelines recommend that patients with persistent symptoms be treated primarily with inhaled corticosteroids and secondarily with other controller medications. For patients with persistent symptoms before the ED visit, only 54.4% reported using an inhaled corticosteroid. At the follow-up call, this proportion improved to 73.8%. Improvement was also seen in the reported daily use of inhaled corticosteroids, which increased from 26.5% to 58.8% of patients with persistent symptoms at the ED visit and follow-up call, respectively. Because these are self-reported, this may overestimate adherence. Although these improvements are encouraging, asthma medication use remained suboptimal for many patients at the follow-up call. A third major finding of this study was that, whereas documented care of the patient’s physiologic state in the ED was good, practices at discharge could be improved. Of those with persistent symptoms who were discharged from the ED, only 49.4% of patient medical records in those with persistent symptoms contained documentation that an inhaled corticosteroid was prescribed or should be continued. The average duration of administration of prescribed oral corticosteroids was 5.6 days for patients discharged from the ED. This duration in the setting of many patients with persistent symptoms and lack of inhaled corticosteroid use could place them at risk soon after discharge for worsened asthma control because of untreated airway inflammation. Asthma is a chronic disease managed by primary care providers or asthma specialists in an office setting, and during severe exacerbations patients typically present to EDs and are treated by emergency physicians. It seems imperative that the bridge between the different sites of treatment be better understood and strengthened. Our findings suggest opportunities for improvement at both sites of care. For the office setting, careful evaluation of the symptoms of a patient with asthma and prescription of inhaled corticosteroids, when appropriate, improve asthma control and prevent exacerbations resulting in ED visits.4,20 For the ED setting, use of inhaled corticosteroids after discharge improves the asthma relapse rate.21,22 In addition, enhanced patient education and referral to an asthma specialist would likely improve the ED patient’s outcome.23 Limitations to this study include the following. First, the administration mode of the RA and OA surveys differed, in that the former was self-administered and the latter was conducted by telephone interview. Such modes were selected because of ease of use and to optimize survey completion rates. In addition, the RA survey had similar reporting compared with a version that was researcher administered (IEDAC, unpublished data, 2002). Second, the time windows for measuring frequencies of symptoms and medication use differed in the RA and OA surveys. This was necessary to avoid measuring symptom and medication use related to the immediate exacerbation alone. Third, the follow-up call rate of 56.0% may bias the results. However, the results in Table 3 are similar in those who had and had not completed the follow-up call 1 month later. This suggests that significant

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bias related to lack of follow-up had not occurred. Last, the convenience sampling used in this study may introduce unknown bias. However, this sampling included different days of the week, times of the day, and data over several months, thereby providing a reasonably generalizable sample. In summary, this study demonstrated that most adults presenting to IEDAC EDs for asthma care had a high burden of disease that preceded and followed the ED visit. The proportion of patients who reported persistent asthma symptoms was high before the ED visit, and this continued at the follow-up call 1 month later. As with other studies, the relapse rate was high. General and asthma-specific healthrelated quality-of-life scores were lower than those of general outpatients with asthma at the 1-month follow-up call. Compared with the ED visit, reported use of medications was improved at the follow-up call. Opportunities to further optimize medication use and ED discharge practices were observed. Overall, these findings portray asthma exacerbations requiring ED care as uncontrolled asthma that deteriorates, improves with ED treatment, but then continues along again as uncontrolled asthma. As patients with such exacerbations move between EDs and offices, efforts at improving the bridge between these sites ought to continue. ACKNOWLEGMENTS We thank our project officers, Seymour Williams, MD, and Steven Redd, MD, both of the Air Pollution and Respiratory Health Branch, Division of Environmental Hazards and Health Effects, National Center for Environmental Health, CDC, Department of Health and Human Services. The authors express great gratitude to the following emergency department teams and IEDAC co-investigators for their expertise and leadership throughout the study: University of Chicago, Chicago, IL, Sapna Gupta, MD; Rockford Memorial Hospital, Rockford, IL, Dennis Uehara, MD; Advocate Christ Medical Center, Oak Lawn, IL, Chintan Mistry, MD; St. John’s Hospital, Springfield, IL, Linda Nordeman, MD; Rush University Medical Center, Chicago, IL, Jane E. Kramer, MD. The authors appreciate the excellent support provided by Annette Miller and Brandon Zagorski as research associates. We thank the late Robert J. Rydman, PhD, for his design and statistical expertise and Robbin M. Stephens, Mary Marre, Robert Sprengel, and Christopher Lyttle, MA, of the Institute for Healthcare Studies at Northwestern University, Feinberg School of Medicine, Chicago, IL, for their support in data management and operation of the telephone survey. REFERENCES 1. Mannino DM, Homa DM, Akinbami LJ, Moorman JE, Gwynn C, Redd SC. Surveillance for asthma–United States, 1980 to 1999. MMWR Surveill Summ. 2002;511:1–13. 2. Emerman CL. Relapse following treatment of acute asthma in the emergency department. J Asthma. 2000;378:701–708. 3. Weiss KB, Sullivan SD, Lyttle CS. Trends in the cost of illness for asthma in the United States, 1985 to 1994. J Allergy Clin Immunol. 2000;1063:493– 499.

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4. National Asthma Education and Prevention Program: Expert Panel Report 2: Guidelines for the Diagnosis and Management of Asthma. Bethesda, MD: National Institutes of Health; 1997. Publication 97– 4051. 5. Global Initiative for Asthma Management and Prevention 2004. Available at: http://www.ginasthma.org. Accessed February 5, 2005. 6. Scribano PV, Lerer T, Kennedy D, Cloutier MM. Provider adherence to a clinical practice guideline for acute asthma in a pediatric emergency department. Acad Emerg Med. 2001;812:1147–1152. 7. Khan MS, O’Meara M, Henry RL. Background severity of asthma in children discharged from the emergency department. J Paediatr Child Health. 2003;396:432– 435. 8. Ford JG, Meyer IH, Sternfels P, et al. Patterns and predictors of asthmarelated emergency department use in Harlem. Chest. 2001;1204: 1129 –1135. 9. Coyle YM, Aragaki CC, Hynan LS, Gruchalla RS, Khan DA. Effectiveness of acute asthma care among inner-city adults. Arch Intern Med. 2003;163:1591–1596. 10. Kwok MY, Walsh-Kelly CM, Gorelick MH, Grabowski L, Kelly KJ. National Asthma Education and Prevention Program severity classification as a measure of disease burden in children with acute asthma. Pediatrics. 2006;117(pt 2):S71–S77. 11. Global Initiative for Asthma Management and Prevention 2007. Available at: http://www.ginasthma.org. Accessed June 10, 2007. 12. Lenhardt RO, Catrambone CD, McDermott MF, Walter J, Williams SG, Weiss KB. Improving pediatric asthma care through surveillance: the Illinois Emergency Department Asthma Collaborative. Pediatrics. 2006; 117(pt 2):S96 –S105. 13. Ford JG, McCaffrey L. Understanding disparities in asthma outcomes among African Americans. Clin Chest Med. 2006;273:423– 430, vi. 14. National Asthma Education and Prevention Program. Expert Panel Report: Guidelines for the Diagnosis and Management of Asthma Update on Selected Topics–2002. J Allergy Clin Immunol. 2002; 110(suppl):S141–S219. 15. Juniper EF, Guyatt GH, Cox FM, Ferrie PJ, King DR. Development and validation of the Mini Asthma Quality of Life Questionnaire. Eur Respir J. 1999;141:32–38.

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16. Adams RJ, Wilson DH, Taylor AW, et al. Psychological factors and asthma quality of life: a population based study. Thorax. 2004;5911: 930 –935. 17. Vollmer WM. Assessment of asthma control and severity. Ann Allergy Asthma Immunol. 2004;93:409 – 413. 18. Emerman CL, Woodruff PG, Cydulka RK, Gibbs MA, Pollack CV Jr, Camargo CA Jr; MARC Investigators. Prospective multicenter study of relapse following treatment for acute asthma among adults presenting to the emergency department. Chest. 1999;115:919 –927. 19. McCarren M, McDermott MF, Zalenski RJ, et al. Prediction of relapse within eight weeks after an acute asthma exacerbation in adults. J Clin Epidemiol. 1998;512:107–118. 20. Sin DD, Man J, Sharpe H, Gan WQ, Man SF. Pharmacologic management to reduce exacerbations in adults with asthma: a systematic review and meta-analysis. JAMA. 2004;2923:367–376. 21. Rowe BH, Bota GW, Fabris L, Therrien SA, Milner RA, Jacono J. Inhaled budesonide in addition to oral corticosteroids to prevent asthma relapse following discharge from the emergency department: a randomized controlled trial. JAMA. 1999;281:2119 –2126. 22. Sin DD, Man SF. Low-dose inhaled corticosteroid therapy and risk of emergency department visits for asthma. Arch Intern Med. 2002;162: 1591–1595. 23. Zeiger RS, Heller S, Mellon MH, Wald J, Falkoff R, Schatz M. Facilitated referral to asthma specialist reduces relapses in asthma emergency room visits. J Allergy Clin Immunol. 1991;876:1160 –1168.

Requests for reprints should be addressed to: Richard O. Lenhardt, MD, MPH Section of Pulmonary and Critical Care Medicine Department of Internal Medicine Rush University Medical Center 1653 W Congress Pkwy Jelke 297 Chicago, IL 60612 E-mail: [email protected]

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