An Analysis of Three Methods for Piont-of-Care Testing Result Entry
in the Clinical Laboratory
By Paul Asbury

Introduction

Point-of-care testing (POCT) has revolutionized the manner with which clinical laboratory scientists, nurses and physicians provide care; giving them the ability to perform an ever-growing array of critical analyses formerly performed exclusively in the core laboratory closer to patient care areas, thus reducing turnaround times for results and empowering healthcare providers with information essential to rapid treatment decisions.

A key component of ensuring that a healthcare enterprise derives the greatest benefit from use of POCT is finding a reliable method to ensure patient results are entered into their hospital information system in a quick and accurate manner. The three methods available to clinicians to post POCT results are through manual entry, keystroke emulation software (scripted interfaces), or an HL7-based bi-directional interface. The content of this article will briefly address the relative advantages and disadvantages of each of these methods and then list considerations that should be included with any plan to implement an HL7-based interface for POCT testing.

Advantages and Disadvantages of Three Result Entry Methods

Manual Entry

One advantage to manual entry is that it is the least-expensive manner to post POCT results to a hospital information system (HIS) or laboratory information system (LIS). Eliminating the need to implement potentially costly software-based solutions, manual entry requires only that personnel certified to review and enter POCT results have access to a workstation loaded with their enterprise's HIS or LIS software to post results.

However, despite the cost savings of this method, there are significant drawbacks to manual entry of results. The accuracy of entries into the HIS/LIS become subject to the human element of data entry errors, which when occurring can cause significant distress and confusion between clinician, provider and patient. Often, individuals required to manually post results are busy with other important and concurrent patient care tasks and are especially vulnerable to distractions while attempting to simultaneously perform all of these functions. Ideally, it would be preferable to have one clinician on each shift devoted exclusively to performing the entirety of POCT analyses to limit the opportunities for errors, but given the current national gap in staffing requirements for many clinical professions and budgeting concerns for many healthcare entities, this simply is not often a feasible option and the staffing situation is not likely to appreciably improve in the immediate future. One possible alternative to having technicians perform immediate result entry while responsible for other tasks is batch entry of an aggregated group of reports at a later time. However, given the urgent nature of many POCT analyses, especially such testing as cardiac enzymes and blood gases, this is often contraindicated in practice as it can serve to delay the posting of results to the patient's EMR, which negates one of the key advantages of performing such testing at or near the patient care area.

Manual entry of results into an HIS/LIS serves as the ultimate fallback method in instances where no interface exists or when the one in place is not functioning. It also can make sense in smaller clinical settings, such as doctor's offices or family clinics, where workload or budgetary considerations make implementation of an automated result entry solution impractical. It requires the most oversight to ensure correct results are posted and is most subject to human error, but in the absence of other methods for result transmission, it provides clinicians the ability to deliver results in a timely manner without reliance on automation to accomplish this task for them.

Keystroke Emulation Software/Scripted Interfaces

Keystroke emulation software, or scripted interfaces, are small programs intended to replicate the process of manual result entry without requiring end user intervention to post and certify POCT analyses. Usually supplied by the POCT vendor's information technology specialists, these programs are customized for the unique interfaces of a given enterprise's HIS/LIS software and are programmed to initiate at the update of the POCT software result database and log in (utilizing a user account customized for the interface) to complete entry and certification of the test results. The most obvious advantage of using scripted interfaces is the elimination of end user manual entry of results into the HIS/LIS, also helping to mitigate data entry errors for busy technologists. Most scripted interfaces originate from vendor workstations included with POCT instruments that are networked into the enterprise's LAN to allow for discovery of the HIS/LIS software. Another benefit to using scripted interfacing is that the cost of development and time to implementation are usually significantly less than implementation of a true bi-directional HL7 interface.

However, there are some drawbacks to using keystroke emulation software in place of HL7 messaging that should be considered before a decision is made. One notable downside to scripted interfaces is that the software is not equipped to adapt to timing errors which can prevent it from successfully accessing the HIS/LIS software to write its results. Such software follows a rigid, step-by-step sequence of programmed actions to log in to the HIS/LIS, find the proper clinical modules, enter the patient data into relevant result screens and then finalize the results for posting the patient's EMR. If there is any sort of situation (such as network congestion or server lag) which causes a disruption between the script's coded wait interval and the time it takes to access each screen in the HIS/LIS software, it can result in data either being unsuccessfully written to the HIS/LIS, or worse, incorrect data being written into result fields, especially if a given test profile (such as cardiac enzyme panels) has multiple results to be simultaneously entered. If such a scenario becomes a frequent occurrence, then the script may need to be adjusted to reflect more accurate timing intervals, which takes the interface off-line during the re-development period.

One other limitation of scripted interfaces is the fact that such programs are usually coded for a limited number of attempts to write a patient result to the HIS/LIS. When the POCT workstation result database is updated, scripts then initiate to connect to the HIS/LIS and enter the patient results. When this is completed successfully, then the POCT database usually reflects the outcome of the attempt on the POCT workstation control program. However, if the result is unsuccessful and the POCT workstation software reflects this outcome, in order for the script to once again attempt to write to the HIS/LIS, user intervention is often required to again initiate (or re-transmit) such an attempt. Though this often does not require manual entry of results on the part of end users, it does require a level of vigilance on the part of technologists to ensure that each result successfully completed by the POCT analyzer is accurately reflected on the patient's EMR in the HIS/LIS in a timely manner.

In practice, scripted interfaces are usually quite reliable and cost-effective interface solutions for enterprises whose POCT volumes are not sufficient to justify the implementation of HL7 interfaces or where budgetary constraints demand the greatest balance between automation and accuracy of results. Scripted interfaces must be thoroughly tested for correct timing with HIS/LIS access intervals, frequently monitored to ensure their results are both accurate and timely and reviewed to ensure that all of the POCT testing performed by the analyzer has indeed been written to the HIS/LIS.

HL7 Interfaces

Systems utilizing the Health Level 7 (HL7) protocol exchange data specific for healthcare information across TCP/IP between software applications. For POCT, this data typically originates from programs included with vendor-supplied terminals and is interfaced either directly to an HIS/LIS or through the use of third-party HL7 messaging integration software called middleware. If implemented, middleware serves to convert inbound and outbound HL7 messages (carrying patient demographic data and test results) into formats understood by both vendor software and the HIS/LIS.

When successfully implemented, HL7 interfaces provide healthcare enterprises with the most reliable automated method for writing patient's POC results to an HIS/LIS. Requiring little to no user intervention to ensure results are entered and finalized into patient records and demanding less administrative oversight than scripted interfaces, HL7 interfaces reduce the administrative load on technologists, allowing them to concentrate on sample testing and all but eliminate the potential data entry errors associated with manual result entry. Monitoring of the messaging queue is handled by software and data exchange between the POC workstation and HIS/LIS is initiated and completed either directly between origin and destination or through the implementation of middleware applications, helping to ensure that critical patient data is posted in a timely fashion. The inclusion of a dedicated interface for POC testing can also result in better return on investment for an enterprise due to the reduction in technologist's time spent either manually entering results (especially for POC devices that run a large menu of diagnostic testing) or having to consistently check to ensure scripted interfaces have successfully completed all pending patient entries.

For all of the advantages of HL7 interfaces, there are important considerations that must evaluated before a decision is made to invest in such technology. Implementation planning for POCT must be carefully coordinated between decision makers in several departments in a healthcare enterprise. Typically such projects include the enterprise's laboratory director, hospital information technology director, laboratory information systems representative, network administrator and the laboratory's point-of-care testing coordinator. For the POCT and middleware vendors, participants usually include a hospital account representative and interface specialist. For the HIS/LIS vendor, interface specialists and other account specialists may become part of the planning team.

HL7 interfaces often require a significant contract investment between enterprise and POCT vendor, and if middleware is necessitated, a separate investment in software from that vendor must also be completed. Though the actual structure of each enterprise's plan will depend on its individual needs, an implementation diagram will typically include steps similar to the list below (this list assumes the POCT vendor(s) and middleware provider(s) are already in place):

1. Planning committee draws up a comprehensive diagram to ensure connectivity between systems, number of test patients to be included and quantity of each individual assay(s) are to be included.
2. POCT, middleware and HIS/LIS vendors, enterprise IT specialists and prepare their respective systems to ensure interoperability. For the POCT vendor, this would involve ensuring all POCT terminal software is equipped with any necessary modifications for HL7 connectivity and network access. For any needed middleware vendors, this involves preparation of their software to successfully translate the inbound and outbound HL7 messages to and from POCT and HIS/LIS vendor software. For HIS/LIS vendors, this involves ensuring that incoming HL7 messages (patient results, either from POCT software or middleware) are routed to the proper modules in their software. (Note: As an example, for MEDITECH environments, this would be an NMI interface routed to the LAB module.) For enterprise IT specialists, they must ensure connectivity either for the POCT software and/or middleware applications through assignment of requisite internal IP address/port combinations and preparation of network hardware (such as cabling) to allow the results to flow to the HIS/LIS through a secure delivery method (often through use of a virtual private network or other encrypted tunneling application).
3. Once connectivity and interoperability have been established for all applications, then laboratory personnel can begin transmitting test patient results to ensure delivery, accuracy and confirmation in the HIS/LIS. If the testing is successful, then the interface can be put into a production environment with a high level of confidence from all parties that the implementation was successful.

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