Asthma and lower airway disease
Age-related differences in clinical outcomes for acute asthma in the United States, 2006-2008

https://doi.org/10.1016/j.jaci.2012.01.061Get rights and content

Background

Little is known about the effect of age on acute asthma outcomes.

Objective

We sought to investigate age-related differences in the emergency department (ED) presentation and clinical outcomes for patients with acute asthma.

Methods

We analyzed the 2006-2008 Nationwide Emergency Department Sample, the largest, all-payer, US ED and inpatient database. ED visits for acute asthma were identified with a principal diagnosis of International Classification of Disease, ninth revision, Clinical Modification code 493.xx. Patients were divided into 3 age groups: children (<18 years), younger adults (18-54 years), and older adults (≥55 years). The outcome measures were in-hospital all-cause mortality, near-fatal asthma-related events (noninvasive or mechanical ventilation), hospital charges, admission rates, and hospital length of stay.

Results

There were an estimated 1,813,000 visits annually for acute asthma from approximately 4,700 EDs. The estimated overall annual number of in-hospital asthma-related deaths was 1,144 (0.06%); 101 died in the ED, and 1,043 died as inpatients. By age group, there were 37 asthma-related deaths per year in children, 204 in younger adults, and 903 in older adults. Compared with younger adults, older adults had higher mortality, had higher rates of near-fatal asthma-related events, had higher hospital charges, were more likely to be hospitalized, and had a longer hospital length of stay (P < .001 for all). After adjusting for comorbidities, older asthmatic patients had a 5-fold increased risk of overall mortality (adjusted odds ratio, 5.2; 95% CI, 4.0-6.9), compared with younger adults.

Conclusions

Older adults with acute asthma have a substantial burden of morbidity and mortality. With the US population aging, there is an urgent need for targeted interventions for this high-risk population.

Section snippets

Study design and setting

We conducted a retrospective cohort study using data from the 2006-2008 Nationwide Emergency Department Sample (NEDS),13 a component of the Healthcare Cost and Utilization Project (HCUP) sponsored by the AHRQ. The HCUP-NEDS is nationally representative of all community hospital-based EDs in the United States, which is defined by the American Hospital Association as all nonfederal, short-term, general, and other specialty hospitals.14 The NEDS was constructed by using administrative records from

Patient and ED characteristics

The 2006-2008 NEDS sample contained 1,195,113 ED visits for asthma from 1,813 US EDs. After the weighting procedures, there were an estimated 1,813,000 visits annually for asthma from approximately 4,700 US EDs. In the weighted analysis the mean age of patients making these visits was 29 years, and 55% were made by women. Eighteen percent were admitted to the hospital, and the mean of their hospital LOS was 3.5 days. On average, the estimated overall number of in-hospital asthma-related deaths

Discussion

In this nationally representative sample of more than 1 million ED visits by patients with acute asthma, we found that older patients had higher ED and overall mortality, higher ED and overall charges, higher admission rates, and longer hospital LOS compared with younger adults. These findings were partially explained by differences in comorbidities; however, in multivariable and sensitivity analyses older age remained a strong predictor of higher morbidity and mortality in ED patients with

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    Supported by grant no. R03HS020722 from the Agency for Healthcare Research and Quality. The content is solely the responsibility of the authors and does not necessarily represent the official views of the Agency for Healthcare Research and Quality.

    Disclosure of potential conflict of interest: C. A. Camargo, Jr, is a consultant for Dey, Genentech, Merck, Novartis, and Pfizer and has received research support from GlaxoSmithKline and Sanofi-Aventis. The rest of the authors declare that they have no relevant conflicts of interest.

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