Infectious Disease-Related Emergency Department Visits of Elderly Adults in the United States, 2011-2012

OBJECTIVES: To investigate the frequency of infectious disease (ID)-related emergency department (ED) visits of elderly adults in the United States. DESIGN: Cross-sectional analysis. SETTING: Nationwide emergency department sample in 2011-12. PARTICIPANTS: Individuals in the ED aged 65 and older with a primary diagnosis of an ID. MEASUREMENTS: ID-related ED visits, hospitalizations, hospital-based mortality. RESULTS: During 2012, a weighted estimate of 3,123,909 ED visits for IDs was calculated in elderly U.S. adults. This accounted for 13.5% (3.1 million visits) of all ED visits of elderly adults; this burden was higher than that for myocardial infarction and congestive heart failure combined. The rate of ID-related ED visits was 7,231 per 100,000 elderly adults. The most-common diagnoses were lower respiratory infections (26.2%; 95% confidence interval (CI) = 25.7-26.6%), urinary tract infections (25.3%, 95% CI = 25.0-25.7%), and septicemia (18.9%, 95% CI = 18.3-19.6%). Of all ID-related ED visits, 1,786,657 (57.2%, 95% CI = 56.6-57.7%) resulted in hospitalization. The leading cause of hospitalization was septicemia, accounting for 32.2% (95% CI = 31.1-33.3%) of all ID-related hospitalizations through EDs, followed by lower respiratory infections (27.8%, 95% CI = 27.2-28.4%). Overall, 123,894 individuals (4.0%, 95% CI = 3.8-4.1%) died during their ED visit or hospitalization. Of these, septicemia was the leading cause of mortality (74.7%, 95% CI = 73.8-75.6%), followed by lower respiratory infections (15.2%, 95% CI = 14.6-15.9%). Analysis of the 2011 data gave similar results for the burden of ID-related ED visits, hospitalizations, and mortality. CONCLUSION: Using a nationally representative sample, it was found that the public health burden of IDs in elderly U.S. adults was substantial, as measured by ED visits, subsequent hospitalizations, and hospital-based mortality.