Chest
Volume 135, Issue 1, January 2009, Pages 57-65
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Original Research
Asthma
Asthma Presentations by Adults to Emergency Departments in Alberta, Canada: A Large Population-Based Study

https://doi.org/10.1378/chest.07-3041Get rights and content

Background

Asthma is a widespread disease with a prevalence of approximately 7 to 10% in adults. Exacerbations are common in the emergency department (ED) setting. The objective of this study was to describe the epidemiology of asthma presentations to EDs made by adults in the province of Alberta, Canada.

Methods

The Ambulatory Care Classification System of Alberta and provincial administrative databases were used to obtain all ED encounters for asthma during 6 fiscal years (April 1999 to March 2005). Information extracted included demographics, ED visit timing, and subsequent visits to non-ED settings. Data analysis included descriptive summaries and directly standardized visit rates.

Results

There were 105,813 ED visits for asthma made by 48,942 distinct adults, with an average of 2.2 visits per individual. Most patients (66%) had only one asthma-related ED visit. Female patients (61.2%) presented more commonly than male patients. The gender- and age-standardized visit rates declined from 9.7/1,000 in 1999/2000 to 6.8/1,000 in 2004/2005. The welfare and Aboriginal subsidy groups had larger age-specific ED visits rates than other populations. Important daily, weekly, and monthly trends were observed. Hospital admission occurred in 9.8% of the cases; 6.4% had a repeat ED visit within 7 days. Overall, 67.4% of individuals had yet to have a non-ED follow-up visit by 1 week. The estimated median time to the first follow-up visit was 19 days (95% confidence interval, 18 to 21).

Conclusions

Asthma is a common presenting problem in Alberta EDs, and further study of these trends is required to understand the factors associated with the variation in presentations. The important findings include an overall decrease in the rates of presentation over the study period, disparities based on age, gender, and socioeconomic/cultural status, and the low rate of early follow-up. Targeted interventions could be implemented to address specific groups and reduce asthma-related visits to Alberta EDs.

Section snippets

Data Sources

Data are available through the government-funded health plan in the province of Alberta, Canada. All Albertans access health care at no personal cost in a uniform single-payer health system.

The Ambulatory Care Classification System (ACCS)16 is a system for tracking the use of ambulatory care visits to government-funded facilities within Alberta. All ED encounters in > 100 provincial EDs are entered into computerized abstracts that constitute the majority of records. Using a uniform protocol,

General Trends

During the study period, the Alberta adult population increased (Table 1) and the yearly number of Alberta adults that visited the ED for any reason grew from 1,184,473 to 1,338,588. Asthma-related ED visits decreased from 21,218 to 16,301, accounting for 1.8% to 1.2% of the total visits.

Overall, 105,813 ED visits for asthma were made by 48,942 distinct adults, with an average of 2.2 visits per adult (median, 1; IQR, 1 to 2; maximum, 322). The majority of adults (n = 32,351, 66.1%) visited the

Discussion

Using a large provincial database, this study explored the epidemiology of adult asthma seen in > 100 EDs in a Western Province of Canada. With 105,813 ED visits during the 6 years, an adult visited an Alberta ED every 30 min for acute asthma. This study identifies some important epidemiologic trends and outcome information not previously described. First and foremost, this study identified an overall decrease in the rates of presentation over the study period. Despite increasing Alberta

Acknowledgment

The authors greatly appreciate the efforts of Yan Jin and Sylvia Wilson at Alberta Health and Wellness in facilitating access to the data. We appreciate the cooperation of The COPD and Asthma Network of Alberta (www.canahome.org), and especially Ms. Eileen Gresl (COPD and Asthma Network of Alberta Manager) in facilitating involvement of these decision makers.

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  • Cited by (0)

    This work was performed at the University of Alberta, Edmonton, AB, Canada. This work was made possible by an operating grant from the Canadian Institutes of Health Research and funding from The Lung Association, Alberta and Northwest Territories.

    This study is based in part on data provided by Alberta Health and Wellness. The interpretation and conclusions contained herein are those of the researchers and do not necessarily represent the views of the government of Alberta. Neither the government nor Alberta Health and Wellness express any opinion in relation to this study.

    Reproduction of this article is prohibited without written permission from the American College of Chest Physicians (www.chestjournal.org/misc/reprints.shtml).

    1

    Dr. Rowe is supported by the government of Canada as a Twenty-First Century Canada Research Chair.

    2

    Dr. Rosychuk is supported by the Alberta Heritage Foundation for Medical Research as a population health investigator.

    3

    Dr. Rowe has received research funding and speaking fees from AstraZeneca, GlaxoSmithKline, and Abbott; none of the other authors declare any potential conflicts of interest.

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