On October 17, 2014, I posted a note discussing the usefulness of a reverse feed of clinical data from the EHR to the LIS (see: Reverse Feed" of Clinical Data from EHR to the LIS -- Will This Ever Happen?). I commented that I had first heard about the "reverse feed" from Dr. Ulysses Balis who is the Director of Pathology Informatics at the University of Michigan Medical School. He submitted an interesting comment to my note which I am now elevating to the level of a note. --BAF
Indeed, I proposed on the fundamental need for reverse feeds (and also reverse-federation, specifically) from the EHR back to the LIS as far back as 2007. This need is made obvious, when one considers the present state, where pathologists and laboratorians are being compelled to sift through one or more clinical systems, in addition to the LIS, in order to review all the underlying diagnostic data needed to make a full and complete report or diagnosis. In the absence of having convenient access to such information, the outcome is both predicable and obvious: reports are generated where the clinical information in foreign/disparate information systems has not been reviewed [by the pathologists generating surgical pathology reports], sometimes leading to glaring errors and inconsistencies (e.g. a bone biopsy not being clinically correlated with the radiographic impression, which itself might be the primary pathognomonic body of evidence) because the pathologist didn't bother to look up the case in the EHR or RIS.
At [the University of Michigan], we are actively developing workflow models that are purpose-built around reverse EHR-to-LIS interfaces and plan to use one such interface from the EHR to enable a pathologist's cockpit for the evaluation of medical liver biopsies. Other exemplars will hopefully come into being in logical succession. In time, as the number of use-cases grow and as the need becomes obvious to all, from a workflow perspective, the hope is that this construct will become commonplace. An important distinction of this type of interface, as opposed to a traditional LIS outbound results interface, is that the incoming clinical data from the EHR to the LIS is ephemeral. As soon as the pathologist or laboratorian is finished in their review of such clinical data, it is discarded. This is done to ensure that the EHR remains the referential single source of truth (SSOT) for all clinical information across the enterprise. Should the lab need subsequent access to clinical data, the reverse feed can again be utilized to refresh the view, with it always guaranteed to contain the most up-to-date data.
Ul raises an important point with regard to a proposed interface at the University of Michigan from the EHR to the LIS. He indicates that the clinical data copied to the LIS will be ephemeral. By this he means that it would be discarded after review in pathology so that the EHR would remain as the single source of truth (SSOT) for all clinical information. Here's a definition of SSOT from the Wikepedia (see: Single Source of Truth):
In Information Systems design and theory Single Source Of Truth (SSOT) refers to the practice of structuring information models and associated schemata such that every data element is stored exactly once (e.g., in no more than a single row of a single table). Any possible linkages to this data element (possibly in other areas of the relational schema or even in distant federated databases) are by reference only. Thus, when any such data element is updated, this update propagates to the enterprise at large, without the possibility of a duplicate value somewhere in the distant enterprise not being updated (because there would be no duplicate values that needed updating).
When test results are transferred to from the LIS to another system such as the EHR, the process is always prone to errors. Some of these errors will be caught during the periodic validation of the LIS-EHR interface but such validation is never foolproof. Ul Balis has referred to the HL-7 interface between two systems as a data shredder (see: The EMR as a Data Shredder: Implications of a Single-Source-of-Truth Policy). As one example, formatting errors are common in the transfer of microbiology test results that are often in tabular format.
The most important interface for the LIS is the one to the EHR because this latter database is usually the only source of lab test results for hospital clinicians. This interface should only be validated by lab professionals because only they are trained to understand lab data in terms of accuracy and correct formatting. Let's assume that, in addition to the EHR, a hospital has a clinical data repository or warehouse that contains lab data. Such a database can not be used for patient care unless the lab data stored there is supplied by the LIS with the interface validated by pathology personnel. Ul understands this SSOT principle because he states, with regard to the reverse feed to the LIS, that "the EHR remains the referential single source of truth (SSOT) for all clinical information across the enterprise." Another important reason for mandating that the clinical data that is copied from the EHR to pathology is ephemeral, as Ul point out, is that clinical data that is acquired later may be modified or updated.