Point-of-Care Testing: Trends in Assay systems

Point-of-care testing has demonstrated great potential for improving clinical efficiency and patient outcome. Since the first portable blood glucose meter, numerous POCT systems have come to the market. From the glucose meter to today’s quantitative POC immunoassay systems, advances made in both biochemistry and optoelectronics have brought about tremendous improvements to POC testing, and enabled results comparable to those from central laboratory systems. Today, POC testing leads the growth within the whole diagnostic testing marketplace.¹ This growth has expanded from larger care facilities to now include smaller sites such as doctor’s offices, clinics, and shopping center pharmacies.

This expansion of POC sites to more diverse and remote locations will require new Information Technology (IT) infrastructure so that assay results can be shared with other care facilities. Today, most physician offices and retail clinics still rely on paper records or manual data entry. The established healthcare IT infrastructure is only available to hospitals and central laboratories, whereas smaller point-of-care sites are isolated from the larger healthcare network. A sophisticated data infrastructure connecting remote test results to all critical healthcare providers is crucial to the sustaining growth of the POC market.

The need for modern healthcare IT systems at all care facilities has recently become more pertinent by the 2009 federal grant of $18 billion in incentives to create a more widespread use of electronic health records within health care organizations.² Starting in 2011, organizations that demonstrate certified electronic health record systems in a meaningful way are eligible for an $18,000 Medicare credit, which is slowly reduced until 2015. After this date, sites that do not demonstrate electronic health record systems will experience 1% to 3% penalties in Medicare reimbursements.

This incentive to incorporate EMR will increase the demand for a POC data exchange infrastructure and, along with it, instrumentation that seamlessly communicates with the larger healthcare system. In general, larger healthcare sites have already invested in this IT infrastructure, where it can be used to connect the assay instruments to the laboratory database. Yet at smaller point-of-care sites, initial cost and ongoing support overhead often inhibits adoption of such infrastructure. Small sites also tend to have fewer trained workers using CLIA-waived instruments, as well as minimal IT budgets. Therefore, in order for smaller POC sites to adopt a connected health record system, instrument designers are challenged to create instruments at the proper cost, while being much easier to install and use than corresponding equipment at larger sites.

Instrumentation is essential to connecting the diagnostic assay to the data management system, while at the same time providing an appropriate user interface to the clinician. Three main components of a diagnostic instrument that deserve discussion are: the analysis of the assay; the instrument interface; and the method of sending the data to the outside world.
 

Analysis, Interface
As assays become more complex and require enhanced sensitivity, the instrument plays a more important role in providing proper calibration, corrections, and error checking while the assay is running. Gone are the days of using human vision and variable lighting sources to guess if a faint line exists. Today’s instruments provide quantitative, repeatable results using either a single scanning detector or a more modern image-based detection system. Real-time corrections are also available to enhance assay sensitivity and minimize the time it takes to obtain accurate results. In addition, assays and instruments are more often designed to work together so that these optimizations are integral to the overall performance of the system.

The users of these next-generation diagnostic instruments will demand features guided by personal electronic devices that they use at home. Users are now accustomed to sophisticated electronic devices that include color touch screens, intuitive menus, and automatic wireless connectivity. Yet the point-of-care marketplace has additional requirements for ease-of-use, including automatic calibration of the instrument, instruments that assist in user training, and lock-out of untrained clinicians. Additionally, the instrument can collect and store results or quality control data that is useful to both the point-of-care site as well as the assay manufacturer.
 

Connectivity
The more diverse point-of-care sites will require more varied methods of network connections to the general healthcare IT system. While larger sites may have well-established connectivity options available, smaller sites may not be willing to invest in such a system, yet still would prefer the benefits of automatic connectivity. New instruments will need to provide multiple options for transmitting data, perhaps via IEEE 802.11 (Wi-Fi) to an internal database server, or via the cellular network to an external secure database. Flexibility of transmission protocols is needed while maintaining data security by proper encryption. The result should be an instrument that negotiates automatic data transmission to all care sites that need the results.

With an instrument being central to the analysis, interface, and connections of point-of-care assays, instrumentation plays a greater role as the central hub between the assay, user, and greater healthcare network. As more assays and instruments are placed in POC sites, the growing instrument volume will shift the manufacturing industry from building low volume, expensive products with long product cycles to higher volume, lower cost instruments that may be replaced more frequently. In other words, the manufacturing model becomes more like the consumer electronics model, creating more opportunities for the manufacturers of these new medical devices.

Since more assay measurement systems are being designed to be used with instruments in high volume, design-for-manufacturing principles become more relevant to the success of such systems. The challenge for designers is to reduce the cost of diagnostic assay reader systems to enable smaller POC sites to adopt new diagnostic methods. This must be done while maintaining the quality of instruments and providing the proper FDA documentation of all components, processes, and results.

Despite the challenges in the design and manufacturing of diagnostic POC instruments, the trend is clearly moving toward assays that require analytical instruments to improve assay performance and value. The next generation POC test instruments will combine laboratory quality performance with sophisticated connectivity/data management solutions with interfaces that are simple and easy to use. Designers and manufacturers of these diagnostic assay systems must be prepared to meet the demand for higher volumes of instruments. By connecting point-of-care to central care, a unified healthcare system will help to drive down healthcare cost and improve patient outcome.

Alverix Inc.
San Jose, CA
alverix.com

¹ http://www.ivdtechnology.com/article/15th-anniversary-essay-marketplace-and-business-issues.
² http://www.ama-assn.org/ama/pub/advocacy/current-topics-advocacy/hr1-stimulus-summary.shtml