I am an emergency physician and medical epidemiologist in the injury prevention and control program at the Centers for Disease Control and Prevention (CDC) in Atlanta. One of our major programmatic responsibilities and challenges is improving the accuracy, completeness, timeliness, and accessibility of emergency department (ED) data for public health surveillance of injuries. These data are needed to monitor the incidence, causes, and effects of injuries and evaluate the effectiveness of preventive countermeasures. ED data have many other potential uses, including public health surveillance of infectious diseases, asthma, ischemic heart disease, drug- and alcohol-related emergencies, and other acute medical problems. In the event of mass casualty incidents, such as may occur with a terrorist attack, EDs are a primary data source for rapid needs assessment and mobilization of a coordinated, community-wide response. However, variations in the way that data are entered in ED record systems impede collection, communication, and re-use of ED data for these various, secondary purposes. To foster greater uniformity, CDC's injury prevention and control program is coordinating a public-private partnership that has developed recommended specifications for many data elements in ED records. Data Elements for Emergency Department Systems, Release 1.0 (DEEDS) is the initial product of this broad-based collaborative effort.
DEEDS was posted at a CDC web site in August 1997 and published in hard copy form two months later. Since then, select specifications from DEEDS have been incorporated into the LOINC database, the Health Level 7 (HL7) Implementation Guide for Claims Attachments, and the forthcoming HCFA Notice of Proposed Rule Making for HIPAA-mandated claims attachment standards. The ED attachment proposed by HCFA is essentially a subset of DEEDS data elements. DEEDS also is serving as source material for statewide ED data standardization efforts in North Carolina and Massachusetts, and DEEDS specifications have been adopted for use in CDC-funded injury surveillance projects in several states. The vendor community's response to DEEDS has been uniformly positive, and although we have not yet measured the extent to which DEEDS specifications have been incorporated into commercial products, several vendors report DEEDS compliance including at least one that reported this before our specifications were finalized and published.
A guiding principle in the DEEDS development effort is that the primary function of an ED record system is to store clinical data and facilitate their retrieval during direct patient care. Hence, DEEDS' scope of coverage focuses on data elements in current clinical use, and the 156 data elements in DEEDS are organized in the approximate temporal sequence of data acquisition during an ED encounter. A structured format is used to document each data element, including a concise definition, specification of data type and field length, a description of when data element repetition may occur, coding specifications for coded elements, and reference to any data standard or guideline used to define the data element and its field values. To the fullest extent possible, specifications for DEEDS data elements incorporate national standards for health care data, particularly standards applicable to electronic patient record systems. Data types and other relevant specifications conform to HL7 Version 2.3, and an appendix maps DEEDS data elements to HL7 fields and segments. Other standards used in DEEDS include the U.S. Bureau of the Census industry and occupation codes, Office of Management and Budget standards for classifying race and ethnicity, the X12 health care provider taxonomy, LOINC codes for laboratory result types, and the ICD-9-CM external cause of injury and condition codes.
In some instances, when a standard terminology or code set was unavailable for use in DEEDS, we developed a recommended set of terms and codes. For example, DEEDS includes its own code set for mode of transport to the ED (ground ambulance, helicopter ambulance, etc.) and patient acuity (requires immediate evaluation or treatment, requires prompt evaluation or treatment, etc.). In still other instances, additional research and development are needed to design terminology or coding specifications or select a set of terms and codes from available candidates. Work is needed on chief complaint, medication identifiers, patient outcomes, and several other coded data elements. Chief complaint is particularly important because the patient's reason for seeking ED care is a major factor in triage decision-making, a key determinant of resource use and service intensity, and in the aggregate provides a crucial unit of analysis for evaluating episodes of care. We believe that with adequate support a field-ready set of chief complaint terms and codes can be identified or developed in two to four years. Terminology could be selected from existing vocabularies as long as they allow representation of undifferentiated complaints, that is, health problems for which etiologic attribution is premature. For example, chest pain may not be attributable to a specific cause at the outset of an ED encounter, and representing this lack of differentiation is crucial. Also important is ease of use and reproducibility of a chief complaint system; it must function effectively in a high volume clinical environment with multiple users working at various levels of clinical experience.
The initial release of DEEDS is intended to serve as a starting point. Further work is needed to expand the scope of DEEDS' coverage so it provides comprehensive coverage of all types of data entered in ED records, including images, wave forms, medical device measurements, and other data not covered in the initial set of specifications. The public-private partnership used to develop DEEDS and our reliance on existing health data standards set a precedent for future revision and expansion. We plan to begin work on the next version later this year and anticipate completion by late 2000 or early 2001.
Daniel A. Pollock, M.D.
National Center for Injury Prevention and Control (F41)
Centers for Disease Control and Prevention
Atlanta, GA 30341
(770) 488-4031, (770) 488-4338 (fax)