PEDIATRICS Vol. 107 No. 6 June 2001, pp. 1357-1362

Short-Term Outcomes After Acute Treatment of Pediatric Asthma

Martha W. Stevens, MD^* and Marc H. Gorelick, MD, MSCE^{, §}

From the ^* Department of Pediatrics, Division of Emergency Medicine, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania; the  Center for Clinical Epidemiology and Biostatistics, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania; and the ^§ Department of Pediatrics, Division of Emergency Medicine, A.I. duPont Hospital for Children, Wilmington, Delaware.

	ABSTRACT

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Context.  The short-term course of pediatric patients after emergency department (ED) treatment for acute asthma has not been comprehensively documented; most previous studies have limited outcomes to ED length-of-stay, hospital admission, and relapse.

Objective.  To describe symptom persistence, medication use, functional disability, follow-up, and relapse in these children in the 2 weeks after acute treatment and ED discharge.

Design.  Randomly selected, prospective cohort from September 1996 to August 1997; follow-up telephone interviews at 1 and 2 weeks.

Setting.  A large, inner-city children's hospital emergency department.

Patients.  Random sample of pediatric asthma visits requiring ED treatment but not admission; 457 were eligible, 388 with complete follow-up (85%); final sample included 367 patients after multiple visits deleted.

Main Outcome Measures.  Details of symptom persistence, functional disability, medication use, relapse, and routine follow-up.

Results.  Results included significant morbidity: 23% (95% confidence interval [CI]: 19, 27) with cough and 12% (95% CI: 9, 15) with wheeze persistent at 2 weeks; 20% (95% CI: 16, 24) with decreased activity at 1 week; 45% (95% CI: 39, 51) missed >2 and 24% (95% CI: 19, 29) 5 days of school or day care; 17% (95% CI: 13, 21) spent 3 days in bed; 54% (95% CI: 47, 60) of caretakers missed at least 1 and 18% (95% CI: 13, 24) missed >2 days of school or work; and 32% (95% CI: 28, 38) of patients were still using greater than baseline medication at 2 weeks. Reported relapse rates were averaged at 13% (95% CI: 10, 17) with 3% (95% CI: 1, 5) admitted. Routine office follow-up was poor: 29% (95% CI: 25, 34) had had a visit; 48% (95% CI: 43, 54) reported no visit/none planned.

Conclusions.  A considerable proportion of inner-city pediatric patients discharged from the hospital from the ED after standard treatment for acute asthma had poor short-term outcomes. Conventional markers of successful ED treatment, such as avoiding hospital admission or relapse, do not adequately describe outcomes of acute care. The patient-oriented measures described here may provide more useful indicators of outcome in the evaluation of acute asthma care.  Key words:  acute asthma, outcomes, emergency room, follow-up, symptom persistence.

Asthma is the most common chronic illness in children,¹ with national prevalence estimated at 4.3%² and an inner-city prevalence of active disease of 8.6%.³ Previous research has documented the substantial morbidity of pediatric asthma, particularly related to acute exacerbations of the disease, with an estimated annual 1.6 million emergency department (ED) visits and over 200 000 hospitalizations among children with asthma.^2,4,5 In addition, data from the 1988 National Health Interview Survey showed that children with asthma experienced 10.1 million days of school missed annually, substantial limitations in activity, and increased risk of poor school functioning.⁶

Recent large, multicenter studies^7,8 have provided more detailed information about chronic symptoms and morbidity, medication and compliance, and health care access and use but have not focused on the morbidity after an acute exacerbation. Asthma-specific instruments to measure pediatric quality of life have been developed, but they do not quantify specific short-term clinical outcomes.^9-12 The majority of previous studies examining outcomes after acute asthma treatment have limited measures to ED discharge, hospital admission, and relapse (return for unscheduled medical care).^13-22

To date, the short-term course of the pediatric patient discharged after outpatient treatment for an acute asthma exacerbation has not been comprehensively documented. Because the success or failure of treatment and prevention strategies should be evaluated with respect to the ability of the interventions to improve patient outcomes, the identification and description of these short-term outcomes may assist ongoing efforts to develop more discriminative tools for the critical evaluation of asthma management interventions in randomized clinical trials or in other observational studies.

The purpose of this study was to describe the persistence of symptoms, use of medications, functional disability, and relapse experienced by children in the 2 weeks after discharge to home from an ED visit for acute asthma.

	METHODS

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This was a prospective cohort study of patients with acute asthma exacerbations treated in the ED of a large (~54 000 annual visits), inner-city academic children's hospital. The cohort was made up of a random sample of 2- to 18-year-old patients with asthma who required treatment for an acute asthma exacerbation but were able to be discharged to home at the end of their ED visit. Asthma was defined as a previous medical doctor diagnosis of asthma or at least 2 previous episodes of wheezing treated with inhaled -agonists. Patients were not included if they were asymptomatic (no ED treatment for asthma required), had any contraindication to the use of routine asthma medications including -agonists or systemic steroids, or had other significant chronic cardiopulmonary diseases that may have contributed to their symptoms (such as cystic fibrosis or cardiac disease). To obtain a representative sample of participants presenting across all seasons, times of the day, and days of the week, patients were enrolled and consent for follow-up was obtained by ED respiratory therapists in 24-hour periods evenly distributed between August 1996 and August 1997. The 24-hour periods or study days were selected using random number tables. Charts of all ED patients presenting on study days were reviewed within 72 hours and eligible asthmatics not captured in the ED were contacted for enrollment by phone.

Demographic, historic, and treatment data were collected on standardized respiratory/asthma charts filled out by the ED physician during the ED visit. Training in the use of this chart and regular chart review for completion was done by the primary investigator (M.W.S.). The asthma practice guidelines in use in our ED at the time of the study were based directly on the expert panel reports from the National Asthma Education and Prevention Program, Guidelines for the Diagnosis and Management of Asthma.²⁵ During the study, treatment in the ED followed standard of care for all patients with acute asthma, including frequent -agonist treatments, early use of systemic steroids for incomplete initial response, and routine ED discharge instructions including the recommendation for the patient to follow-up with the primary asthma care provider within 1 week of the ED visit. At the time of this study, it was not our standard of care to prescribe changes in maintenance medications for routine use outside the period of the acute exacerbation. Decisions regarding hospital admission were not altered during the study and were based on the patient's response to treatment, previous history or risk factors, and continued stability after treatment over an observation period after their last bronchodilator treatment.

Participants were contacted by telephone by the primary author (M.W.S.) for 2 interviews at 5 to 7 days and 13 to 15 days after the ED visit. The follow-up data collected during the telephone questionnaire included the patient's course at home: continued symptoms of cough and wheeze, medication use, functional disability of child and caretaker (days of school missed, days in bed, days of limited activity, decreased sleep, days of caretaker's missed work or school, and days of special childcare arrangements), and relapse. Interviews were conducted with the caretaker except in a few cases when the caretaker identified the child as more familiar with their course at home since ED discharge. Data were also collected regarding home exposures to pets and smoke, the site of the child's routine asthma care, and more detailed asthma history and household demographic information not available from the chart.

Data Analysis

In the primary analysis, each outcome variable was described: continuous variables summarized by the mean, range, and standard deviation, or by median and interquartile range (IQR) if not symmetrically distributed based on visual inspection of the histogram. Categorical variables are summarized by frequencies and 95% confidence intervals (CIs) calculated by exact binomial method.

Secondarily, the association of several frequently used measures of asthma severity or poor symptom control (number of ED visits and hospitalizations in the last year, frequency of exacerbations at home, frequency of oral steroid courses, and time since last hospitalization) with a defined poor outcome (prespecified group of the study outcomes) was examined. The Kruskal-Wallis test was used to compare an ordinal scale of these severity measures between those with and without poor outcome (poor outcome was defined as relapse with admission or wheezing for at least 1 week and coughing for at least 2 weeks after the ED visit; decreased activity for at least 2 weeks; or missing 5 or more days of school or day care). The level of significance was set at P  .05.

	RESULTS

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Study Sample and Demographics

During the 92 study days, a total of 457 eligible patients (~20% of the yearly total number discharged with the diagnosis of an asthma exacerbation from this ED) were identified and 388 (85%) were contacted and follow-up completed. Those lost to follow-up included 19 (4%) with inaccurate or disconnected phone numbers, 3 (1%) who refused consent or had no phone, and 47 (10%) who were not available on multiple attempts. Of the total 388 visits with completed follow-up, 19 participants had multiple visits (17 with 2 visits, 2 with 3 visits). It was decided a priori that at the completion of the study, patients with multiple visits would have just 1 of their visits randomly chosen by study number to remain in the database. The deletion of the other visits gave a final sample size of 367. The demographics for this sample are outlined in Table 1.

Symptom Persistence

Caretakers were asked about the number of days to cough and wheeze resolution after the ED visit at both 1- and 2-week follow-up telephone calls. As seen in Fig 1, nearly one half (46%; 95% CI: 41 ,51) reported persistent cough and approximately one third (32%; 95% CI: 26, 36) reported persistent wheeze at 1 week, with a sizable number with persistent symptoms still at 2 weeks (23% and 15%, respectively). Twenty-nine percent of children were reported to have both cough and wheeze persisting together at 7 days; 12% at 2 weeks.

View larger version (23K): [in this window] [in a new window]   Fig. 1.   Symptom persistence and functional disability.

Functional Disability

Of the total, 290 children were reported to be enrolled in day care or school. During the 2 weeks after the ED visit, the median number of missed days was 2 (IQR: 1-4; range: 0-15) with nearly one half of the children (45%; 95% CI: 39,51) missing 3 or more days, and nearly one quarter (24%; 95% CI: 20,30) missing 5 or more days (Fig 1). There was no significant difference in the number of days missed between children in school (over 5 years old) and those in day care or preschool (under 5 years old). Of the 224 caretakers working outside the home or going to school, 54% (95% CI: 47,61; n = 223) missed at least 1 day and 18% (95% CI: 13,24) missed 3 or more days. Caretakers working or in school needed to make special arrangements for childcare for at least 1 day in 17% (95% CI: 13,23) of cases. If such arrangements were needed, the median was for 2 days (IQR: 1-3; range: 1-10).

There was a wide range in the number of days children spent in bed after their ED visit; most (and the median) spent no days in bed, the maximum was 10, the IQR was 0 to 2. Seventeen percent (95% CI: 13,20) spent 3 or more days in bed and 7% (95% CI: 5,11) spent 5 or more days in bed (Fig 1). The plot of symptoms, days spent in bed, and days of school or day care missed shows their roughly parallel persistence after the ED visit. Table 2 summarizes reported decreased activity and sleep disruption at 1 and 2 weeks after the ED visit.

Medication Use

The use of a maintenance medication (defined as medication taken every day between periods of increased wheezing or cough) was reported in 46% of children (169/367; 95% CI: 41, 51): 18 used albuterol only and 147 reported use of cromolyn and/or an inhaled steroid with or without daily albuterol (96 cromolyn, 18 inhaled steroid, and 33 cromolyn and inhaled steroid).

During both follow-up contacts, caretakers were asked about the child's current medication use, particularly the use of rescue medications or -agonists. If the use of asthma medication was greater than at baseline (more frequent dosing or more kinds of medications), it was recorded as greater than maintenance use at 1 or 2 weeks (Table 2). Medication use at 2 weeks included 118 children (32%) still using inhaled albuterol at least 3 times a day.

Prednisone was recorded as prescribed on the ED charts on 283 of 365 visits (77%; 95% CI: 73, 82). Caretakers reported use of steroids for 3 to 5 days if prescribed in 95% of cases, 4% reported not filling or not completing the prescription, and 1% did not know if it had been used. Eighty-four of 85 caretakers correctly reported that no steroids had been prescribed (1 discrepancy with ED records).

Relapse and Routine Follow-Up

Relapse and routine postexacerbation follow-up data are summarized in Table 3. Routine follow-up with the patients' primary asthma care physician after an ED visit was poor with less than one third reporting a visit with their primary asthma care provider by the time of the 2-week follow-up interview. Some reported to have planned for a follow-up visit soon after, but nearly one half reported no follow-up and no plans for a future visit.

Overall Outcome

Composite classifications of short-term outcome were defined in advance. Poor outcome was conservatively defined as at least 1 of the following: relapse to medical care resulting in hospital admission, persistent symptoms (1 week or more of wheezing and 2 weeks or more of cough), or significant functional disability (decreased activity persisting at 2 weeks, or missing 5 or more days of school or day care). A total of 85 of the 367 patients (23%; 95% CI: 19, 28) had a poor outcome by this definition. A second, slightly different definition of poor outcome (cough or wheeze for 2 weeks or more, or relapse with admission, or decreased activity for at least 2 weeks, or missing >2 days of school/day care) would have included 180 of 367 patients (49%; 95% CI: 44, 54).

Asthma Severity and Outcome

In addition to describing the short-term outcome of patients after their ED visit, we also wanted to look at the relationship between these outcomes and previously identified markers of poor control or increased chronic asthma severity. Table 4 summarizes some of these commonly identified markers in our study sample. When asked about episodes of wheezing requiring more than baseline or maintenance medication use at home, 11% reported a frequency of at least once a week and 41% at least once a month. Information about ED visits over the last year was available for only 240 of the sample (65%), but the group of visits with these data missing was not significantly different with respect to age, sex, frequency of wheezing episodes at home, last admission, or frequency of prednisone use. Available data showed 15% with 6 or more ED visits in the last year, approximately one quarter of the patients had at least 4 visits, and one quarter had none. The reported approximate frequency of prescribed courses of oral steroids was at least once a month in 7%, 4 or more a year in 26%, and 24% with no previous history of use. The last time a course of steroids was prescribed was reported to have been within the last month in 26% and within the last 3 months in 43%.

A significant association was shown between those with the first (or more stringent) definition of overall poor outcome and frequency of wheezing episodes at home, frequency of courses of oral steroids, and number of ED visits for acute symptoms in the last year (Table 5). The association between poor outcome and the total number of previous asthma admissions approached significance, but there was no association between poor outcome and time since last admission. There was also no association between poor outcome and the demographic categories of age (as a continuous variable or grouped categorically as preschool or school age), gender, race, presence of a single caretaker, mother and father in the home, maternal grandmother in the home, high school education status of the caretaker, or the reported presence of pets or smoke in the home. The same pattern of significance was found with the second definition of poor outcome.

We also separately examined patients grouped as frequent or infrequent ED users. Frequent users, the subset of children with 6 or more reported ED visits over the last year, were significantly younger with a median age of 6 years, compared with 8 years of the rest of the group (P = .043). As would be expected, frequent ED users also had significantly higher levels of some of the markers of greater severity or poor control (frequency of courses of steroids, frequency of exacerbations treated at home, and total number of hospitalizations). Patients with frequent ED use were not significantly different from the rest of the sample in gender, race, proportion with a single caretaker, age or level of schooling of the primary caretaker, the proportion having insurance or a doctor for routine asthma care, or the severity of their acute symptoms as indicated by number of ED treatments or prescription of prednisone during their ED visit. As previously shown, patients in our sample significantly increased their chance of a poor outcome as the number of their previous ED visits in the last year increased. Fifteen percent (15/100; 95% CI: 9, 24) of patients with 1 or no previous ED visits in the last 12 months met the first definition of poor outcome compared with 39% (14/36; 95% CI: 24, 55) in the group with 6 or more previous visits.

The question of the relationship of acute severity in the ED with overall outcome was also examined. Available markers of exacerbation severity from the ED visit included the number of albuterol nebulized treatments given during the visit and the use of prednisone in the ED. Neither of these markers had significant correlation with either of the 2 conglomerate categories of poor outcome or with the individual outcome categories of time to cough or wheeze resolution or relapse to medical care.

	DISCUSSION

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These data show a surprisingly high level of morbidity reported by caretakers in the 2-week period after an ED visit in children judged well enough to be discharged to home after treatment for an acute asthma exacerbation. Depending on the definition, our sample had 23% to 49% of such patients with a poor outcome. Previous studies have noted the association of frequent ED use and the outcome of relapse,^13,21,22 but even our patients with histories of infrequent ED use in the last year had relatively high short-term morbidity. Relapse to medical care, a traditional measure of outcome after ED treatment for asthma ranging between 4% and 30%,^{414-16,20,21,24} was not high (13%) in this study and in no way suggested the otherwise substantial morbidity of persistent symptoms, school days lost, decreased activity, or disruption of the work or school schedule of caretakers. Poor outcome in our sample was not significantly associated with markers for the severity of the exacerbation but was shown to be associated with markers of chronic severity or poor control.

Our study specifically targeted an inner-city sample of ED patients with acute exacerbations for short-term follow-up, and therefore it was expected that children with moderate and severe asthma would be more heavily represented than in population, clinic, or school based surveys. Although results of our study may not be generalizable to these other settings, our ED population is similar to other inner-city pediatric ED populations. In our sample, 77% of participants had an ED visit and 29% were hospitalized within the last year. This can be compared with the National Cooperative Inner City Asthma Study,⁷ with patients recruited both from the ED and nonacute clinic visits, which had 66% with an ED visit and 17% with an asthma admission in the last year. Eggleston et al⁸ and Mak et al²⁶ both used school surveys to identify children with asthma in urban Baltimore or Washington, DC and found 44% to 58% with an ED visit in the last 6 months and 7% to 12% with a hospital admission during the last 12 months. National data from the Child Health Supplement to the National Health Interview Survey in 1988 showed a 9% to 10% rate of hospitalization over the preceding year.²³ Oral steroid use within the last 3 months (43%) was also high in our study; the National Cooperative Inner City Asthma Study reported 59% use in the last 3 months in participants recruited from the ED and 19% in clinic (nonacute) recruits. Our sample was demographically similar to these other urban study populations in average age, minority race, caretakers, insurance, and identification of a primary physician. Although the overall chronic asthma severity of this population was higher than clinic or school-based population samples, our average admission rate (28%) and relapse rate are comparable to other urban acute care centers,⁴ suggesting that our discharged population was not unusually symptomatic or ill.

The only other article found in the literature specifically describing the outcomes of symptoms and medication use after acute ED asthma treatment in children was published in 1991 by Butz et al.²⁴ In their study, theophylline alone was prescribed at discharge for bronchodilation in two thirds of patients. Nevertheless, we found rates of persistence of symptoms similar to those that they reported: wheeze in 33% to 44% and cough in 65% to 70% at 3 to 5 days, and 7% to 22% with wheeze and 37% to 54% with cough at slightly over 2 weeks. High rates of persistent symptoms and functional disability call into question the use of outpatient status or discharge from the ED as a marker for successful acute treatment for asthma in children.

Despite prolonged symptoms, functional disability, and medication use, reported rates of routine follow-up after the ED visit were poor with 71% of patients having no follow-up by the time of the 2-week telephone interview. National guideline²⁵ recommendations include follow-up with the patients' health care provider within 3 to 5 days of all ED visits to review asthma history, maintenance medications and their use, home symptom monitoring, and daily management and action plans to prevent exacerbations and urgent care visits. The effect of inadequate primary health care provider follow-up may be reflected in histories of frequent ED use, the low proportion on maintenance inhaled corticosteroids, and the high level of morbidity in our study population. Interventions to improve follow-up may in turn lead to improved short-term patient outcomes of acute exacerbations.

Future interventions suggested by these data would be most effectively and efficiently applied if targeted at those individuals at high risk of excessive short-term morbidity. Although this study showed significant associations between patients with poor short-term outcomes and certain indicators of poor symptom control, none of these markers alone was highly predictive. A larger study currently underway at our institution aims to identify predictors of short-term outcome and to develop a model for optimal disposition in the acute care setting (inpatient care vs observation unit, home nursing, or discharge).

Our results indicate that rates of admission and relapse, traditional measures of successful ED asthma treatment, do not adequately assess the existing morbidity of patients discharged from the ED. High levels of several types of short-term morbidity were reported commonly in our population and clearly impact the daily life of patients and their families. These poor outcomes were not found to be associated with markers of exacerbation severity but were associated with chronic markers of poor control or higher chronic asthma severity.

Short-term outcomes after current standard-of-care acute outpatient treatment for asthma have not been previously been well documented. In describing these outcomes, we hoped not only to delineate further the existing morbidity, but also to suggest measures helpful in the generation, design, and evaluation of diverse asthma care interventions addressing issues, such as asthma medications, utilization of care, treatment plans, or environmental triggers. If these short-term outcomes are found to occur frequently in other populations and if changes in these short-term outcomes impact long-term or chronic severity, they will become useful, and relatively easily obtained, standard measures of outcome in the assessment of modifications in acute pediatric asthma care.

	FOOTNOTES

Received for publication Mar 3, 2000; accepted Nov 1, 2000.

Reprint requests to (M.W.S.) Emergency Services, CH-04, Children's Hospital and Regional Medical Center, 4800 Sand Pt Way NE, 5371, Seattle, WA 98105. E-mail: msteve{at}chmc.org

	ABBREVIATIONS

ED, emergency department; IQR, interquartile range; CI, confidence interval.

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