National Study of U.S. Emergency Department Visits With Diabetic Ketoacidosis, 1993–2003

Abstract

We analyzed the emergency department component of the 1993–2003 U.S. National Hospital Ambulatory Medical Care Survey (NHAMCS). Our institutional review board waived review of this analysis. Methodological details are described elsewhere (6–8). Briefly, NHAMCS uses a four-stage sampling strategy covering geographic primary sampling units, hospitals within primary sampling units, emergency departments within hospitals, and patients within emergency departments. Hospitals were stratified by region, presence of emergency department, ownership type, and size. Within each stratum, hospitals were selected with a probability proportional to the number of emergency department visits. Data were collected during randomly assigned 4-week periods. Data forms include demographic information, emergency department disposition (i.e., admission, transfer, and discharge), and up to three ICD-9 discharge diagnoses. For the present analysis, we identified DKA visits based on ICD-9 code 250.1x, the unique code for DKA, in any of the diagnosis fields. This methodology has been utilized in prior Centers for Disease Control (CDC) analyses (3,9).