Case Definitions

The NEMSIS Technical Assistance Center provides case definitions for scenarios that are often tracked in EMS for performance improvement or research purposes. Each case definition includes specific criteria recommended by the NEMSIS TAC to promote consistency across the industry. The case definitions were developed through discussions with subject matter experts and consultation of published research studies and other resources.

The case definitions are described in plain English as well as XPath and SAS code. Since the NEMSIS standard is XML-based, if there is any ambiguity or inconsistency between the plain English, XPath code, or SAS code, the XPath code is authoritative. The case definitions generally “cast a wide net,” in that they may contain records that would be excluded when applied to specific purposes. “General Filters” define criteria that can be combined with the case definition criteria to further filter records by the following attributes, for example:

  • 911 calls, interfacility calls, etc.
  • Transports, non-transports, etc.
  • ALS, BLS, etc.
  • Pediatric, adult, geriatric, etc.

The case definitions are compatible with NEMSIS versions 3.4.0 and 3.5.0.