This page is part of the FHIR Specification (v0.0.82: DSTU 1). The current version which supercedes this version is 5.0.0. For a full list of available versions, see the Directory of published versions

?.? Purpose

The FHIR USLab Public Health Report (FHIR ELR) Implementation (FHIR ELR) is based upon the USLab Report Implementation and repeats most of that content here as well as the additional requirements, specifications and standards, and on providing the implementation guidanceneeded to transmit reportable laboratory observations to appropriate US local, state, territorial and federal health agencies using using FHIR in the RESTful framework. FHIR ELR facilitates the inclusion of information necessary for public health reporting in the larger test order - test result process between ordering providers/laboratories and performing laboratories to ensure that the data is available to be sent to PH when necessary. Harmonizing the technical specifications (format and vocabulary) for the test order (order placer sends order to lab), test result (lab sends result to order placer), and reportable test result (lab sends result to PH) enhances interoperability and data quality thus improving the overall laboratory result reporting process for both the sender and the receiver.

This implementation is not specific to any pathogen or reportable condition and is applicable for most biological and chemistry reportable laboratory observations. Each state and territory has requirements for laboratories to report certain findings to health officials. Authority to establish a list of reportable conditions and to specify the content of those reports resides with the individual public health jurisdiction. Reports made to Public Health come in two forms: case reports (not the subject of this guide), and laboratory reports related to reportable conditions. Reporters can access further information about reportable conditions at the website for their own Public Health jurisdiction relevant to their service area. Additionally, this implementation does not replace the need for each public health jurisdiction to document additional constraints of their specific implementation.

?.? Audience

This guide is designed for use by analysts and developers who require guidance on FHIR resources, elements and specific extensions relative to the Laboratory Results Interface (LOI) initiative, HL7 V3 Lab Normative Standard and electronic laboratory reporting (ELR) requirements to Public Health. Users of this guide must be familiar with the details of the FHIR Specification and resource processing. This guide is not intended to be a tutorial on that subject.

?.? Conventions

This guide adheres to the following conventions:

?.? Key Technical Decisions

?.?.1 Profile And Component Architecture

This guide uses FHIR profiles on the following resource to define a minimum set of requirements to enable the successful exchange of laboratory orders:

The main objective is to ensure that EHR systems and Laboratory systems can exchange laboratory orders with minimum if any modifications from one combination to another combination of software, while maintaining flexibility to enable software developers to provide more capabilities using the same core Resource definitions.

?.?.2 Use Of Vocabulary Standards

This guide calls for specific vocabulary standards for the exchange of laboratory information such as LOINC and SNOMED. Standard vocabularies, particularly coded laboratory tests and their results, enable automated decision support for patient healthcare, as well as for public health surveillance of populations. Value Sets resource are provided as part of this implementation.

?.?.3 Snapshot Mode

FHIR only functions using snapshot mode - updates are communicated by sending a complete copy of the instance with the new data filled in. If a correction and/or status update to Obsveration Resource is necessary, the DiagnosticReport with all references to all Obsveration Resource, even if previously sent, shall be resent with the correction and/or current status and/or current values. For example, when a Complete Blood Count with manual differential is ordered, the blood count will be released and then at a later time the manual differential will be performed and released. When the blood count is released the DiagnosticReport will reference only the Observation Resources for the count as final results. When the differential is completed, the DiagnosticReport will reference all previous Observation Resources as well as the new Observation resources - in this case the blood count and the differential results.

Examples of a partial, final and corrected DiagnosticReport Bundle.

?.?.4 Scope Of Implementation

Due to receiving system variations and need, this guide does not specifically indicate for each field whether to store it or not. This is left to the individual system's scope and purpose.

?.? Use Case

This use case is based upon existing regulatory requirements for laboratories to report "reportable" laboratory test results to local public health agencies. This use case was developed as a collaborative effort between CSTE and CDC and the HL7 Pubic Health and Emergency Response Workgroup.

?.?.1 Scope

The scope is the sending of "reportable lab results from a laboratory to a PublicHealth agency is US Realm.

?.?.1.1 In Scope

?.?.1.2 Out of Scope

?.? Actors

There are two actors that have responsibilities related to the conformance profiles defined in this document:

?.? Orders for Ambulatory Care Use Case and Context Diagrams

Figure 2-1. Use Case Diagram

Figure 2-1. Use Case Diagram

Figure 2-2. Context Diagram

Figure 2-2. Context Diagram

?.?.1 User Story

A Provider (orderer) may enter a laboratory order into an ambulatory DSS. A laboratory requisition is generated (paper or electronic) and is communicated to the laboratory. The information in the laboratory requisition is entered manually or captured electronically into the LIS. After the specimen(s) has been collected and, if necessary, shipped or delivered to the laboratory, the laboratory processes the specimen(s). If the specimen is satisfactory for testing the laboratory will perform the test. Prior to successful completion of a test, communication may also be necessary to indicate cancellation, failure to perform the test and the related reasons; for example if the specimen is either not appropriate for the ordered test, or otherwise unsatisfactory the rejection of the specimen will be communicated using USlabReport profile. Order cancellation notifications should be communicated using the USLabOrder profile. The laboratory performs or attempts to perform the test(s). If testing is successful, results are obtained and entered/released in the LIS. An authorized person at the laboratory reviews and approves the laboratory test results, or the certifying laboratory reviewer of record in the case of an auto-verification process, to be sent to the provider and any non-ordering providers requested in the laboratory order. The results are either pushed or pulled into the provider's DSS (results receiver). The DSS incorporates the results into the patient's electronic record. The provider logs into his/her DSS and views the laboratory results in order to inform patient care decisions.

The laboratory result is determined to be a reportable laboratory result for the patient's and/or the provider's public health jurisdiction. The results sender, e.g., LIS or EHR, transmits the results to the appropriate public health jurisdiction. The public health jurisdiction's ELR-PH Receiver incorporates the results in their disease surveillance system allowing for the appropriate follow up by the public health jurisdiction.

?.?.1.1 Use Case Assumptions

?.?.1.2 Pre-Conditions

?.?.1.3 Post-Conditions

?.?.1.4 Functional Requirements

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?.?.1.4.1 Sequence Diagram

Figure N-N: Scenario 1 Sequence Diagram

FHIR ELR of reportable
            Laboratory Test(S)

?.? Error Handling

Refer to the FHIR Specification on REST status codes and the use of the OperationOutcome Resource when further information about the transaction error is needed. Note to balloters: The error handling specifications are currently not fully defined for this implementation.

?.? Code Systems And Value Sets

Successful message implementation requires that transmitted messages (message instances) contain valid values for coded fields. For further discussion on Using codes in FHIR refer to the FHIR specification.

?.?.1 LOINC

The use of the Logical Observation Identifiers Names and Codes (LOINC) code system is required where a LOINC code is available for the Observation.name, i.e. the being resulted. Appropriate status is defined in the LOINC Manual Section 11.2 Classification of LOINC Term Status. If a local coding system is in use, a local code should also be sent in addition to the LOINC to help with identification of coding issues. When no valid LOINC exists the local code may be the only code sent.

While data storage requirements in the EHR will not be addressed in this guide, it is recommended that LOINC codes be stored in or accessible by the EHR for the following reasons:

  1. If the result is related to a reportable condition and the laboratory provides a LOINC code,
  2. Meaningful Use Stage requires the EHR to send the LOINC code to public health.
  3. LOINC codes may be used for secondary data exchange purposes and other partner exchange agreements.

?.?.2 SNOMED CT

The use of the SNOMED-CT code system is required where a SNOMED-CT concept code is available for Observation.valueCodeableConcept, i.e. the actiual coded result. If a local coding system is in use, a local code should also be sent in addition to the SNOMED-CT concept code to help with identification of coding issues. When no valid SNOMED-CT exists the local code may be the only code sent.

SNOMED CT is required for specimen source term elements, Specimen.type and Specimen.Collection.sourceSite where a SNOMED-CT concept code is available.

?.?.3 UCUM

The use of the UCUM (Unified Code for Units of Measure) code system is required for reporting units of measure in Observation.quantity.

?.?.4 Value Sets

The value sets for this implementation as well as USLabOrder and USLabPHReport can be found on the USlab Implementation page. In additionm, mappings to the HL7 Version 2.5.1 Implementation Guide: S&I Framework Lab Results Interface are also available.

?.? Additional Implementation Guidance

?.?.1 Confirmatory and Reflex Testing ( Including Culture/Susceptibility Testing)

Definition: Additional laboratory testing included in the original test request by reference to specific follow-up testing, e.g. "Urinalysis w/Culture Reflex" as opposed to "Urinalysis" ordered as a standalone test. The decision to perform the reflex or confirmatory test is based upon the results of the initial test and application of a predetermined local or national practice guideline, approved protocol or legal requirement.

An example is provided here for the scenario in which a urine cultire results in the identification of the pathogens: E.coli, x and y and a susceptibilty is performed on all three pathogens. todo..

?.?.2 Add-On Testing

Definition: Additional laboratory testing is requested by an authorized provider (as defined by CLIA and state law) on an existing specimen after the original test request has been submitted to the laboratory. The decision to request additional testing is individual provider driven and based on any number of factors not limited to a test result.

?.?.3 Epidemiological important information from Ask at Order Entry responses

There are several common data elements that have been identified as important data elements for Public Health laboratory reporting that do not have a supported field in the ELR251 message. This data may be available in the Lab Sender system as Ask at Order Entry (AOE) responses for a particular test order. See Ask on Order Questions in USLabOrder. For FHIR-ELR the appropriate AOE answers should be sent along with the actual results as DiagnosticReport.result elements.

?.?.4 Reference test results

The Observation.performer shall be the laboratory where the reportable laboratory results originated. There may be occasions when the sending laboratory needs to transmit and ELR message for reportable results that did not originate from their facility. For example a specimen may be forwarded from one laboratory to a reference lab or to another lab as a "pass-through" test. The criterion for reporting results that did not originate with the sender is subject to the discretion of the local public health jurisdiction.

?.?.5 Clinical Laboratory Improvement Amendments Considerations

In the United States, clinical laboratory testing of human specimens is regulated by the Clinical Laboratory Improvements Amendments of 1988 (CLIA). Several sections of the regulations implementing CLIA impact how electronic laboratory data is formatted for the US Realm and these are outlined in this section. Impacted areas include mandatory test request requirements. CLIA Regulation Specifics.

?.?.6 CLSI Definitions - Quantitative, Semi-quantitative, Qualitative Results

The following defnitions were derived from the CLSI website:

?.?.7 Glossary