Section 1a: Clinical Document Architecture (CDA®)
Section 3: Implementation Guides
HL7 CDA® R2 Implementation Guide: National Health Care Surveys (NHCS), Edition 4 - US Realm
DESCRIPTION
This IG contains templates to represent healthcare data collected by the NCHS within the Division of Health Care Statistics (DHCS). The data are collected through surveys of ambulatory, inpatient, and outpatient care services in the United States: the National Ambulatory Medical Care Survey (NAMCS) and the National Hospital Care Survey (NHCS). These surveys produce nationally representative data to answer key questions about health care utilization for public health professionals, researchers, and health care policy makers.
This implementation guide specifies National Health Care Surveys with three document types:
- Emergency Department Encounter, for data collected by NHCS (NHCS-ED)
- Inpatient Encounter, for data collected by NHCS (NHCS-IP)
- Outpatient Encounter, for data collected by NHCS (NHCS-OPD) and NAMCS
The NAMCS focuses on ambulatory care and is based on a sample of visits to non-federally employed office-based physicians primarily engaged in direct patient care. The National Hospital Care Survey (NHCS) is based on a sample of visits to hospital inpatient, emergency, and outpatient departments. The surveys currently require manual data extraction. Field representatives visit physician practice locations for NAMCS, and hospitals for NHCS, to abstract survey data elements. Data captured include information on patient demographics, vital signs, medical history, reasons for visit, diagnoses, procedures and medications. Data is entered into a computer-based tool that sends data back to NCHS. This process is labor and resource intensive, costly, and does not take advantage of emerging health information technology. NCHS would like to automate this process and collect more data without needing to send field representatives to physician offices/hospitals and allow all selected physicians/ hospitals to participate in the surveys by providing electronic files from their EHR to do so. The surveys contain patient encounter and facility components; this project will focus on the patient encounter components. Data from these surveys are widely used by health policy makers, health service researchers, epidemiologists and health care industry and other interested parties.
ALTERNATIVE NAMES
HL7 CDA® R2 Implementation Guide: National Health Care Surveys (NHCS), Edition 4 - US Realm may also go by the following names or acronyms:
TARGETS
- Centers for Disease Control and Prevention/National Center for Health Statistics
- Health care community, researchers, and policymakers
- EHR, PHR Vendors
- Health Care IT Vendors
- Emergency Services Providers
- Healthcare Institutions (hospitals, long term care, home care, mental health)
- Ambulatory Health Care Facilities (office-based physicians)
BENEFITS
- Creates a standardized format to represent ambulatory, inpatient, and outpatient healthcare data collected by the NCHS within the Division of Health Care Statistics (DHCS), NCHS, part of the CDC
- Enables automation of the survey data collection process by using CDA to streamline the collection of data and increase the sample pool by allowing all providers who participate in the surveys to do so electronically
- Supports physician offices'/hospitals' ability to participate in the NCHS surveys by providing electronic files from their EHRs
IMPLEMENTATIONS/CASE STUDIES
- The Centers for Disease Control and Prevention (CDC)/National Center for Health Statistics (NCHS) sponsored the development of this specification
- CDC/NCHS is collaborating with Epic, Veradigm, and Oracle Health to support implementation activities
DEVELOPMENT BACKGROUND
The NAMCS collects objective, reliable information about the provision and use of ambulatory medical care services in the United States. Findings are based on visits to health care providers at sampled health centers. Previously, sample visits to non-federally employed, office-based physicians were also included.
The NHCS is designed to provide reliable and timely healthcare utilization data for hospital-based settings. Non-federal, non-institutional hospitals with six or more staffed inpatient beds are randomly selected to provide nationally representative data on hospital utilization. Participating hospitals are asked to submit all inpatient discharges and emergency department visits for a 12-month period.
Previous versions of this implementation guide also supported a third survey, the National Hospital Ambulatory Medical Care Survey (NHAMCS) which collected data on the use and provision of ambulatory care services in hospital emergency departments. The data historically gathered by NHAMCS is now collected through the NHCS.
The audience for this implementation guide includes the architects and developers of healthcare information technology (HIT) systems in the US Realm that exchange patient clinical data in hospital, emergency and ambulatory care settings.
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Current Release |
Upgrade Release |
Notes |
Issue Reporting |
|---|---|---|---|
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STU 1.2 |
STU 2.1 |
STU 1.2 Aligns with Promoting Interoperability program requirements. |
https://jira.hl7.org/projects/CDA/issues/ |
|
STU 2.0 |
STU 2.1 |
Current STU 2.0 implementations who want to fix issues with 2.0 submissions should consider upgrading to STU 2.1. |
https://jira.hl7.org/projects/CDA/issues/ |
|
STU 3.0 |
STU 3.1 |
Path to FHIR implementation. |
https://jira.hl7.org/projects/CDA/issues/ |
|
New implementation |
STU 3.0 |
Aligns with Promoting Interoperability program requirements through SVAP. |
https://jira.hl7.org/projects/CDA/issues/ |
|
New implementation |
STU 3.1 |
Net new implementers, path to FHIR implementation. |
https://jira.hl7.org/projects/CDA/issues/ |
|
STU 4.0 |
4.0 |
Path to FHIR implementation. |
https://jira.hl7.org/projects/CDA/issues/ |
RELATED DOCUMENTS
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HL7 CDA® R2 Implementation Guide: National Health Care Surveys (NHCS), Edition 4 - US Realm |
STU DOCUMENTS
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HL7 CDA® R2 Implementation Guide: National Health Care Surveys (NHCS), Edition 4 – US Realm | (Submit Feedback on STU) |
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HL7 CDA® R2 Implementation Guide: National Health Care Surveys (NHCS), Release 1, STU Release 3.1 – US Realm | Expiration Jun 2026 |
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HL7 CDA® R2 Implementation Guide: National Health Care Surveys (NHCS), Release 1, DSTU Release 1.2 – US Realm | Expiration Jun 2026 |
(Download) (5.60 MB) |
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HL7 CDA® R2 Implementation Guide: National Health Care Surveys (NHCS), Release 1, STU Release 3 – US Realm | Expiration Jun 2026 |
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HL7 CDA® R2 Implementation Guide: National Health Care Surveys (NHCS), Release 1, STU Release 2.1 – US Realm | Expiration May 2024 |
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HL7 CDA® R2 Implementation Guide: National Health Care Surveys (NHCS), Release 1, STU Release 2 – US Realm | Expiration May 2024 |
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HL7 CDA® R2 Implementation Guide: National Health Care Surveys (NHCS), Release 1, DSTU Release 1.1 – US Realm | Expiration Jul 2017 |
(Download) (5.94 MB) |
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HL7 Implementation Guide for CDA® Release 2: National Health Care Surveys (NHCS), Release 1 - US Realm | Expiration Jul 2016 |
(Download) (5.83 MB) |
ADDITIONAL DETAILS
SUPPORT FILES
GitHub link for STU4: https://github.com/HL7/CDA-nhcs-4.0
GitHub link for STU 3.1: https://github.com/HL7/CDA-nhcs-1.3.1
GitHub link for STU 2.1: https://github.com/HL7/CDA-nhcs-1.2.1
- https://github.com/HL7/CDA-nhcs-4.0
- https://github.com/HL7/CDA-nhcs-1.3.1
- https://github.com/HL7/CDA-nhcs-1.2.1
See the “_readme.txt” file included in the STU document download for more details.
TOPIC
- Public Health
BALLOT TYPE
- DSTU
- STU
STATUS DATE
2026-02-24RESPONSIBLE WORK GROUPS
PRODUCT TYPE
- Implementation Guide
STAKEHOLDERS
- EHR, PHR Vendors
- Emergency Services Providers
- Health Care IT Vendors
- Healthcare Institutions
- Regulatory Agency
- Standards Development Organizations (SDOs)
FAMILY
- CDA
CURRENT STATE
- Active
REALM
- US Realm