Previous research has shown that ED crowding is widespread throughout the United States and poses a serious threat to the quality of care that is provided. In studies involving adult patients, increased crowding has been linked to decreased safety, effectiveness, and efficiency of care. Patient-centeredness and timeliness of care are also compromised. While most research on the effect of crowding has been centered on the management of adult patients, few studies have explored the crowding–quality relationship in an ED population of children, largely because of the scarcity of quality measures applicable to children in the ED setting.

Acute Asthma at the ED

In the March 2011 Annals of Emergency Medicine, Marion R. Sills, MD, MPH, and colleagues examined the crowding-quality association in an ED population of children with acute asthma exacerbations. The cross-sectional study utilized retrospective data on patients aged 2 to 21 who were treated for acute asthma during November 2007 to October 2008 at a children’s hospital ED. “Asthma is among the most common reasons children seek ED care,” says Dr. Sills. “The disease results in 750,000 ED visits annually in the U.S.”

“Children seen at a crowded ED for acute asthma were less likely to receive timely and effective care than when the ED is less crowded.”

In the study, three processes of care for acute asthma—asthma score, β-agonist, and corticosteroid administration—were reviewed in the context of three quality measures—timeliness, effectiveness, and equity. The measures of timeliness were the percentage of children with acute asthma receiving an asthma score, β-agonist, or steroid within the first hour of arrival to the ED during crowding. Effective care was measured by the percentage of patients receiving an asthma score and the percentage receiving a steroid during their visit. Equity of care was measured by assessing the language spoken by patients, their insurance status, and whether they had a primary care provider.

Children’s Care in Crowded ED

“Children seen at a crowded ED for acute asthma were less likely to receive timely and effective care than when the ED was less crowded,” says Dr. Sills. For the effectiveness measures, the authors observed greater than 80% receipt. For timeliness measures, there were lower rates of timely receipt, ranging from 23% for steroid administration to 64% for β-agonist administration. The median time for asthma score was 53 minutes, for β-agonist administration was 45 minutes, and for steroid administration was 99 minutes. Care received did not appear to be influenced by equity measures.

Patients were 52% to 74% less likely to receive timely care and 9% to 14% less likely to receive effective care when the pediatric ED was at the 75th percentile of the crowding measure than when it was at the 25th percentile. Data comparing the 90th and 10th percentiles of crowding indicated a greater difference in quality of care when measured across a greater range of crowding (Figure).

Crowding Effects Care

“Our analysis shows that crowding exerts a ‘dose-related’ effect on key processes used to measure the timeliness and effectiveness of ED asthma care,” Dr. Sills says. “The results confirm what has been reported on the ED crowding–quality association in adult populations. Our study demonstrated that, as the ED gets more crowded, more children with asthma either are not receiving or experiencing delays in receipt of indicated processes. These data are important because nonreceipt of appropriate, timely care can increase the risk of admission and ED revisits.”

The greatest delay observed in Dr. Sills’ research was in steroid delivery. This may reflect the complexity of the asthma care processes. Asthma scores may be assigned and β-agonists may be administered by nurses or respiratory therapists, but steroid ordering and administration is sometimes a contingent process that involves nurses, respiratory therapists, and physicians.

Optimizing Preventive Care

“Most asthma-related ED visits are preventable, but greater efforts are needed to optimize preventive care,” says Dr. Sills. “EDs are continuing to experience crowding issues because many Americans are using this setting as their primary place to receive care. The ripple effect is profound because crowding impacts other patients who may require more emergent care. Although EDs can mitigate crowding to some degree through efficiency measures (eg, order sets and streamlined front-end operations), the real solutions will come from policy makers, who should seek to incentivize preventive care in the medical home. For example, primary care providers should be rewarded for providing quality asthma care to children. Likewise, patients should be incentivized to engage in good asthma self-management practices.”


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Bernstein SL, Aronsky D, Duseja R, et al. The effect of emergency department crowding on clinically oriented outcomes. Acad Emerg Med. 2009;16:1-10.

Institute of Medicine. Emergency Care for Children: Growing Pains. Washington, DC: National Academies Press; 2007; Accessed September 28, 2011.