Methods and Limitations
We estimated the number of emergency department (ED) visits with diabetes in any of 15 listed diagnoses using data from the National Emergency Department Sample (NEDS) of the Agency for Healthcare Research and Quality. NEDS is a nationally representative sample of U.S. community hospital-based EDs, and the largest all-payer ED database in the United States, containing ~25–30 million records annually. NEDS collects information on geographic, hospital, and patient characteristics as well as the nature of visits derived from State Emergency Department Databases for those "treat and release" ED visits and from State Inpatient Databases for cases admitted to hospitals from EDs. Detailed description on the data is available at http://www.hcup-us.ahrq.gov/db/nation/neds/NEDS_Introduction_2009.pdf.1
ED visits with diabetes as any-listed diagnosis were identified using ICD-9-CM code 250.xx. To determine common reasons for ED visits, we categorized ICD-9-CM codes for first-listed diagnosis using Clinical Classifications Software that is available at http://www.hcup-us.ahrq.gov/toolssoftware/ccs/ccs.jsp#overview. ED visit rates among adults were calculated using two population denominators: the estimates of adults aged 18 years or older with diagnosed diabetes from the National Health Interview Survey (http://www.cdc.gov/nchs/nhis.htm),2 and estimates of the general population aged 18 years or older from the Census. Rates were age adjusted on the basis of the 2000 U.S. Standard Population using age groups 18–44 years, 45–64 years, 65–74 years, and 75 years or older. For persons younger than 18 years, we reported the number of ED visits but not ED visit rates because of the lack of reliable diabetes prevalence estimates for this population.
Because NEDS samples ED visits instead of individual persons, ED visit rates may not necessarily reflect rates per person; that is, persons who had ED visits more than once in a year may be counted more than once. No information on patient's race/ethnicity, type of diabetes, and insulin usage is available from NEDS.
- Agency for Healthcare Research and Quality. Healthcare Cost and Utilization Project. Introduction to the HCUP Nationwide Emergency Department Sample (NEDS) 2009. Available at http://www.hcup-us.ahrq.gov/db/nation/neds/NEDS_Introduction_2009.pdf.
- CDC. National Center for Health Statistics. National Health Interview Survey. Available at http://www.cdc.gov/nchs/nhis.htm.