Core Health Data Elements: Report of the National Committee on Vital and Health Statistics. Executive Summary



The identification, definition, and implementation of standardized data in the health care and health care information fields are long overdue. The increasing use of electronic data, the evolving managed care field, and the growing requirement for performance monitoring and outcomes research have made it imperative that all health data collection activities, where possible, utilize standardized data elements and definitions.

The National Committee on Vital and Health Statistics (NCVHS) has undertaken a first step in bringing together leaders in the field to seek consensus on a small set of data elements that are often considered the core of many data collection efforts. The Committee's goal has been to develop a set of data elements with agreed-upon standardized definitions that, when needed in a data collection effort, can be used to collect and produce standardized data. The intent is not to specify a data set for mandated external reporting; the list of recommended data elements is by no means exhaustive, and, unlike earlier activities, is not a "data set" to be used in a specific setting.

It is the expectation of the Committee that the health care field will find these recommended data elements to be fundamentally important for any collection of person and health care encounter data and will consider these elements and standardized definitions for inclusion in their data collection efforts wherever possible. Favorable input has been received from a wide range of experts, and these elements should be compellingly useful both to states and to provider organizations.


In August 1994, the Department asked the Committee to provide information and advice that will help maximize the utility of core person and encounter data for meeting the Department's responsibilities.

Specifically, the Department charged the Committee to:

  • Review state-of-the-art of widely-used core data sets in the United States and other countries (including coding and formatting features that allow for flexibility);
  • Obtain input, through hearings and other means, from the diverse parties who will report and use standardized data sets;
  • Interact closely with recognized standards-setting groups; and
  • Promote consensus by identifying areas of agreement on data elements and data sets among different stakeholders and areas that will require further research and development before consensus can be reached.

In developing a strategy for accomplishing these tasks, the Committee described a context in which the project would be undertaken that included the following issues:

  • Why such data sets are needed in the current and evolving health care arena;
  • What multiple functions they might accomplish for a variety of different users;
  • What data elements (including definitions, vocabularies and coding structures) they might contain; and
  • What potential problems, such as assuring data quality and preserving confidentiality of identifiable records, can be expected and what approaches might be used to address these problems.

The Core Health Data Elements

The following list of data elements contains those elements selected for the first iteration of this process. Consensus has been reached on definitions for some of these elements; for others, there is much agreement, but definitions must still be finalized; and for a third group, additional study and testing are needed. These elements apply to persons seen in both ambulatory and inpatient settings, unless otherwise specified. For the first 12 elements, with the exception of unique identifier, information may not need to be collected at each encounter. Standard electronic formats are recommended to the extent that they have been developed.


1. Personal/Unique Identifier 2/

2. Date of Birth

3. Gender

4. Race and Ethnicity

5. Residence

6. Marital Status

7. Living/Residential Arrangement 1/

8. Self-Reported Health Status 2/

9. Functional Status 2/

10. Years of Schooling

11. Patient's Relationship to Subscriber/Person Eligible for Entitlement

12. Current or Most Recent Occupation and Industry 2/

13. Type of Encounter 2/

14. Admission Date (inpatient)

15. Discharge Date (inpatient)

16. Date of Encounter (outpatient and physician services)

17. Facility Identification 1/

18. Type of Facility/Place of Encounter 1/

19. Health Care Practitioner Identification (outpatient) 1/

20. Location or Address of Encounter (outpatient)

21. Attending Physician Identification (inpatient) 1/

22. Operating Clinician Identification (inpatient) 1/

23. Health Care Practitioner Specialty 1/

24. Principal Diagnosis (inpatient)

25. Primary Diagnosis (inpatient)

26. Other Diagnoses (inpatient)

27. Qualifier for Other Diagnoses (inpatient)

28. Patient's Stated Reason for Visit or Chief Complaint (outpatient) 2/

29. Diagnosis Chiefly Responsible for Services Provided (outpatient)

30. Other Diagnoses (outpatient)

31. External Cause of Injury

32. Birth Weight of Newborn

33. Principal Procedure (inpatient)

34. Other Procedures (inpatient)

35. Dates of Procedures (inpatient)

36. Procedures and Services (outpatient)

37. Medications Prescribed

38. Disposition of Patient (inpatient) 1/

39. Disposition (outpatient)

40. Patient's Expected Sources of Payment 1/

41. Injury Related to Employment

42. Total Billed Charges 1/

Footnotes: 1/ element for which substantial agreement has been reached but for which some amount of additional work is needed; 2/ element which has been recognized as significant but for which considerable work remains to be undertaken. A lack of footnote indicates that the element is ready for implementation.

Additional data items

While reviewing the draft list of data elements, respondents indicated a number of additional data elements that they felt were important core elements. Examples include information on health behaviors, such as smoking and alcohol consumption; information on preventive services; language ability; severity of illness indicators; provider certainty of diagnostic information; information to link a mother's and infant's charts; information on readmissions and complications. Future projects may undertake to seek consensus among some of these items.


As a result of the process followed in the conduct of this project and based on careful analysis by its members, the Committee has reached the following conclusions:

  • The response to the Committee's activities through both participation in meetings and written comments indicates that the health care information field is solidly in favor of the identification and use of standardized data elements and definitions.
  • The number of standards-setting organizations is growing; however, all who addressed the Committee are actively seeking participation by a 'recognized' leader/group who can forge consensus for the health care information field. But time is short; decisions are being made by organizations now.
  • Response was significant and positive to the Committee's request to review a set of core data elements that were identified after a series of hearings and other information- gathering efforts were completed. Most organizations were supportive in wanting to 'get on board' with standardized data elements.
  • There is already consensus among data collectors and users for a significant number of data elements, especially elements related to person descriptors and to selected information on inpatient and ambulatory encounters.
  • There is less agreement on data definitions, even for data items that have been in the field for years. Definitions must be refined and made available in standardized formats to data collectors.
  • There are data items, such as health status and functional status, that are considered crucial elements, but for which substantial additional evaluation and testing must be undertaken to reach consensus on standardized content and definition.
  • Because they recognize the significance of this project, respondents also recommended a number of additional items that they would like evaluated and possibly included in a core set of standardized data elements.

Recommendations to the Department

1. The Committee recommends that the HHS Data Council:

  • Circulate the report within the Department for review and constructive criticism.
  • Investigate the formation of leadership sites within the Department for each of the standards-setting organizations.
  • Refer the core health data elements recommendations to the National Uniform Claim Committee for their consideration as they study the issue of uniform data elements for paper and electronic collection in Fall 1996.
  • Provide stable resources to the project to establish an interagency work group, with DHSS taking the lead, to work with the key standards-setting organizations in the area of core health data elements.

2. The Committee recommends the following actions specifically related to the core data elements:

  • For those elements that the Committee recommends as being ready to standardize, request each of the data collection entities within the Department to review the set of data elements and to match data contents and definitions with similar items that they are currently collecting or plan to collect. Report to the HHS Data Council on the viability of these elements and definitions being adopted in their program. If a reporting entity is using a different element or definition, explain why their current usage is preferable.
  • Support implementation and testing activities for those data elements for which agreement on definitions has been reached and those for which minimal additional work is needed on definitional agreement. Public and private participants have indicated a willingness to work together to disseminate information, test data elements, and utilize electronic means to ensure the widest dissemination of these activities.
  • For those data elements which have been recognized as significant core elements, but for which there is not consensus on definition, support the formation of a public-private working group to conduct or coordinate additional study or research and to further refine definitions. This group, or a separate group, could also be the focus for evaluating additions to the list of core data elements and for setting up methods for testing and promulgating the final products.
  • Place the Committee's report, elements and definitions on an appropriate departmental Home Page as guidance to the field and as a means of encouraging use and soliciting further comments and suggestions while the report is under review within the Department.

3. Because agreement on a unique personal identifier has been recognized as a key element to the successful establishment of core data elements, and their use, support the formation of a public-private working group to study and provide recommendations in this area.

4. Support the NCVHS in continuing its work in this area, especially using its expertise to discuss research issues, to assist in consensus building, and to participate with the Data Council in the implementation of the core health data element project recommendations.