1998, Volume 9, Number 1
Point-Of-Care Testing: A Review
By Victor Hruszczyk
Point-of-Care Testing (POCT) is a reality. It will continue to grow in scope and use. Economic justifications need to be specific to the test and service site. These analyses need to consider the effects on the entire Healthcare System. As this testing becomes more commonplace, regulatory criteria will change to reflect a shift in quality control responsibility from the user to the manufacturer. Changes in reimbursement for laboratory testing will follow as the paradigm changes to POCT. New tech-nologies will assist with data capture to assure documentation for the medical record and for appropriate billing.
Implementation of any point-of-care test will require a well organized quality assurance plan to demonstrate its positive or negative effects. Multi-department participation and orchestration will be required to implement and assess the program.
For the hospital laboratory, this will bring substantial change to the procedures and practices currently performed. As with any change, however, new opportunities will become available and the system will improve.
Perceived Benefits of POCT
The general principle driving POCT is that "faster is better". The problem when implementing POCT in a particular clinical setting is being able to define "what" is better. The perceived benefits can be classified as:
|Medical Management:||Outcomes are improved due to better patient care|
|Resource Management:||More effective use of diagnostics, beds, etc.|
|Time Management:||Less handling, fewer individuals involved per test|
|Consumer Demand:||Fewer visits, improved compliance|
It is not obvious that every situation imaginable will benefit by moving to POCT. The chore is to evaluate the current condition and compare it to the proposed outcome if POCT is implemented. The literature has an ample supply of experiences with such comparisons. However, since the technology is rapidly evolving and since one author's definition of POCT is different from another's, it is necessary to take some time to sort out exactly what one is describing.
Defining POCT by Location and Usage
Any discussion regarding POCT needs to define what is considered as a point-of-care test. The literature begins in 1984 with the introduction of self-monitored blood glucose tests in diabetic patients (1). Various literature describe "Patient Focused Testing", "Near Patient Testing", decentralized laboratory strategies and various other approaches for rapid testing and reporting as point-of-care tests. Today, the definition is still somewhat vague. The most consistent definition now is based on location - near (next to) the patient. This definition tends to form two distinct usage categories of Intensive Care or bedside testing and convenience testing for clinic use. Our discussion will consider both as POCT. The economics and clinical utility of each are different. The literature that argues the utility of bedside hemo-stasis monitoring for patients undergoing cardiac surgery can not be directly applied to justify the ability for a clinic to perform drug of abuse testing in their office. It is this diversity that is the challenge, being able to justify the particular application for both medical and economic benefit - site by site, test by test.
Defining POCT by Technology
In addition to the categories based on use, POCT instruments can be separated based on their technologies (2). These categories are:
In Vivo Sensors: Recent developments with optical sensor technology and fiberoptics allow the intravascular placement of devices to continuously monitor analytes. Currently, pO2, CO2 and pH can be measured this way. Optical electrodes have been developed for glucose, potassium, lactate and other molecules that eliminate the need for phlebotomy.
Ex Vivo Sensors: These sensors are outside the vascular system and are located in the tubing connected to the patient. Blood is automatically or manually withdrawn into the tubing and is studied by the sensor. In some systems, the blood may be returned to the patient. Various uses in surgery and intensive care situations are envisioned.
In Vitro Testing: These analyzers are usually cart-based systems or portable devices that require that the blood be drawn from the patient and placed into the measuring device. Over 90 Veteran's Administration (VA) medical centers, outpatient clinics and outreach centers across the nation are using a portable laboratory called TraVAlabs to perform this type of testing. The instrument is a 5-foot-long, 2-foot-wide cart equipped with the instruments described in Figure 1 and requires only an electrical outlet to function continuously. The unit has enough portable power for 15 minutes of operation. This type of "near patient testing" requires a skilled laboratory professional to perform the tests and is different from other POCT where the caregiver is the person performing the analysis and not necessarily a laboratorian. For these reasons, we will further define "in vitro POCT" as those tests that could be performed by any trained healthcare provider with a disposable "unit-use light-weight instrument". For this discussion, the definition of POCT will include the limitation that a professional laboratory technologist is not required to perform the test. Although this would eliminate the TraVAlab system, a more restrictive definition enables a better understanding of the labor component when evaluating a POCT scheme with another or against a central laboratory model. The TraVAlab model better fits a "decentralized laboratory" model and is presented here to offer a division between POCT and decentralized laboratories.
|Figure 1: Instruments Included on TraVALab|
|Ektachem DT 60II dry-slide analyzer (general chemistry)
Johnson and Johnson Clinical Diagnostics, Rochester, NY
Ektachem DTSC II (special chemistry)
Johnson and Johnson Clinical Diagnostics, Rochester, NY
Biotrack 512 (routine coagulation, PT and APTT)
Boehringer Mannheim Corporation, Indianapolis, IN
Biotrack 516 (therapeutic drug monitoring)
Boehringer Mannheim Corporation, Indianapolis, IN
DCA 2000 (diabetic monitoring)
Bayer Corporation, Diagnostics Division, Tarrytown, NY
i-STAT clinical analyzer (critical chemistries and hematocrit)
I-STAT, Princeton, NJ
GEM Premier (critical chemistries, blood gases and hematocrit)
Mallinckrodt Sensor Systems, Ann Abor, MI
K-1000 (general hematology and CBC)
Sysmex, Long Grove, IL
Source: Clinical Laboratory News Vol 22, No. 11 November 1996
The Underestimated Scope of POCT
The notion that POCT is a passing fancy fails to account for the size of both the investment made in the diagnostic industry and the menu of tests that are near market. Literature reviews published in 1995 (3) are outdated and have not been replaced with current information. Authors in early 1997 (4) cited "at least 40 companies with POCT products on the market, 20 more with products in development and at least 80 analytes available."
Alexander K. Arrow, MD, a research analyst at Wedbush Morgan Securities, has identified industry trends that favor POCT (5). He reports companies targeting unique niches in the POCT market and projects that most blood samples will be analyzed in a Point-of-Care test setting. He cites four significant advantages for POCT:
- It allows the treating physician to receive immediate test results, enabling immediate treatment decisions.
- It saves the patient an extra visit to the doctor's office or emergency room.
- It saves the aggregate health system money.
- It may give the physician an additional source of revenue.
His work was published in December of 1996 and listed the categories of POCT in Figure 2 . By mid-1997, there was another field bursting onto the scene as bedside coagulation testing (6,7) began to impact outcomes in a favorable way. The advances were so rapid that neither the May 1994 conference (8) on POCT in Philadelphia nor Arrow's 1996 review contained any mention of coagulation POCT.
|Figure 2: Assays Available as Point-of-Care Tests: (5)|
|Electrolytes||Sodium, potassium, chloride, bicarbonate, creatinine, BUN and glucose||The seven most frequently ordered tests on inpatients.The US military requires these for any POCT it buys||Abaxis 3 of 7 Diametrics-2 i-STAT 7 Quantech will offer 7|
|Blood Gases||Oxygen, carbon dioxide and pH||Surgery and ICUs||Diametrics|
|Cholesterol||LDL, HDL and Triglycerides||Routine checkup-standard of care||Cholestech, ChemTrak|
|Drugs of Abuse||NIDA 5 and barbiturates, benzodiazepines||Rapid [15 min] screen. Screening at ERs and employee testing facilities||American BioMedica|
|Cardiac Enzymes||CK, LDH, troponin, myoglobin||6 million ER visits with chest pain each year||Private company developing a desktop unit|
|Osteoporosis Markers||NTx crosslinks||Osteoporosis concerns growing with an aging "baby boomer" generation||Cholestech and private companies|
|HIV||HIV||Current J & J and HomeAccess kits require mail-in [this is outdated in March 1998].||Royce, Calpte, Murex|
|Strep A||Streptococcus pyogenes||Large over-the-counter market for Strep A testing||Quidel and Murex|
|H. pylori||Helicobacter Pylori||Stomach ulcers||BioMerica, Quidel, Meridian, ChemTrak and SKBL Diagnostics|
|Other Quantitative Assays||hCG, PSA, digoxin, pituitary gonadotropins||Outpatient endocrinology, TDM||Biocircuits|
|Other Infectious Diseases||TB, Mycoplasma, C. difficile, E. coli, hepatitis, Chlamydia||Over 8 million new TB cases annually||Cortex, Meridian, Murex|
The Clinical Laboratory Improvement Amendments of 1988 (CLIA) are the federal regulations that dictate the necessary licensure for any clinical laboratory testing. Although the critical care departments can obtain a separate license, it is most efficient to have the clinical laboratory administer the POCT program through its license.
Regulatory Oversight and Documentation of "Waived Tests"
Currently, the CLIA regulations divide tests based on complexity. Some POCT instrumentation is listed in the "waived category". The waived category originally had only eight tests. It expanded to include 13 and may go as high as 50 with the new technologies that are coming to market (9). However, other agencies have been granted deemed status to inspect for CLIA and they have other requirements for POCT.
The least complex regulations are those of CLIA and the Commission on Office Laboratory Accreditation (COLA). For waived tests, CLIA or COLA require that one register with the Health Care Financing Administration (HCFA) and follow the manufacturers' instructions. An inspector may ask to see quality control documentation as described by the manufacturer's instructions.
The Joint Commission on Accreditation of Healthcare Organizations (JCAHO) requires that waived tests have quality control performed daily, documentation of corrective action if there is a QC failure, the ability to trace a result to both a specific instrument and a QC result, and a competency program for all personnel using the instruments. The College of American Pathologists (CAP) treats waived POCT as highly complex tests. CAP requires two quality control results per run, verification of performance parameters (accuracy, precision, reportable range, sensitivity, specificity, linearity, calibration verification and reference range) as well as documenting the competence of personnel and having documentation of results to an instrument and daily QC value. In addition, the CAP requires proficiency testing for each analyte. Electronic controls are acceptable to all of the groups. However, CAP requires documentation that electronic controls are "scientifically acceptable".
Some POCT is defined by CLIA as moderately complex. Again, each deemed authority has slightly different requirements to satisfy their accreditation process. In general, the requirements include site-specific procedure manuals, calibration or checks for calibration every six months, at least a two level QC program with documents and remedial action identified, and a training program for competency including records. The CAP has revised its requirements by issuing a new "Checklist 30" for POCT in January 1997. As issues regarding the new technologies of POCT and traditional QC or QA methods evolve (see QA concerns on page 8), new methods for assuring quality will need to be incorporated into the regulations.
Quicker and more appropriate therapies are expected to reduce the probability that negative clinical outcomes will occur. However, a current laboratory testing program may be meeting the turnaround time requirement for such interventions. It is necessary that a quality assurance program determine what goals are intended to be achieved with a new POCT program and to know exactly what the current performance levels are for these parameters. Individual programs (10) have demonstrated POCT as the unquestionably preferable mode by demonstrating the savings in turnaround time to reductions in operating room time, that is easily translated into dollar savings for the hospital and a medical benefit for the patient. Others have voiced a concern that the cost of complying with regulatory requirements and lost billing due to the displacement of the service from any informatics system may add more to the variable cost (labor and reagents) than is realized (11).
When assessing cost effectiveness, it is necessary to explore more than the cost per test. It is necessary to perform a "total economics" analysis that assesses the costs and benefits per encounter with laboratory testing.
Joseph Keffer, MD, Professor and Chief of Clinical Pathology at the University of Texas has written about such analyses. He makes the following statement in a review of the economic considerations of POCT: Tables 1, 2 and 3 are taken from his article.
|Joseph Keffer, M.D.
"In discussions with laboratorians, one often hears that POCT is being delayed until it is shown to be cost-effective. Although this sounds appropriate, the statement reveals a lack of insight and sophistication with regard to the economic science of cost-effectiveness analysis. It may suggest obstruction.
Economic science explores alternative opportunities to invest limited resources for the purpose of achieving optimal return on the investment. It is all about comparisons. Cost-effectiveness analysis is a method applied to this task. Weinstein and Stason's (13) description is widely considered the primer on the subject for medical application. Recently, Udvarhelyi (14) and colleagues reviewed the medical literature purporting to present cost-effectiveness analysis and found few publications that fulfilled the fundamental definition described by Weinstein and Stason. I reviewed them in another publication (15) in more detail. Table 1 lists the positive and negative costs to be studied and is included for a comprehensive and conclusive study of the cost-effectiveness of POCT. These figures are adapted from a combination of our own experience and extracted from the cost-effectiveness literature. No published studies of POCT approach all relevant issues.
Even when complete, published studies in the general medical literature are intrinsically subjective because, inevitably, values must be assigned to benefits such as extended life, quality of life, or decrease in projected expenditures. Furthermore, studies typically are deficient in failing to address alternative options. They fail to test "robustness" of the comparisons. In reviewing POCT studies purporting to assess cost-effectiveness analysis, we find bedside blood gas testing compared with establishing a comprehensive satellite laboratory fully loaded with capitalization of new and diverse equipment and fully staffed for around-the-clock operation. Many alternatives are not addressed that may be more cost-effective. In another common scenario, cost of labor to perform POCT is reported as nonexistent or minimized when performed by ward staff while contrasted with the central laboratory burden of labor costs. In other reports, bedside glucose testing is found to be cost-effective by assigning a large value to dietary and nursing costs attributed to delays in central laboratory testing.
It should be obvious that cost-effectiveness analysis studies do not establish cost-effectiveness of the technology. Such studies are site and institution specific. Whether we should even incur the costs of doing a cost-effectiveness study should be assessed first. The benefits of POCT are often intangible and difficult to value in dollars...."
|Table 2: POCT Benefits for the CEA Equation|
Improved turnaround time
Eliminates physician "refocusing" from one patient to another in 90 minute spans
Improved patient management: Improved patient satisfaction
Decreased transfusion in cardiac surgery
Resultant improved productivity: example increased throughput in the clinic or ER
Decreased OR time and overtime for staff waiting for laboratory results
Physician/nurse job satisfaction by empowerment, decreased "burnout" and turnover
Decreased dietetic services for customized service, decrease nursing time waiting for meals/lab values
Improved relations between the laboratory and the clinical personnel with reversal of the "disappointment index"
Improved outcomes: morbidity, mortality
Improved efficiency in patient throughput resulting from shorter waiting time in the ER improved "word of mouth" reputation and increased patient flow
Overcome shortage of Medical Technologists
Decreased errors: transcription of orders, clerical transfer, transportation, breakage, repeats and dilutions
Benefit of alternative investment opportunities
Improved communications: immediate reporting, direct specimen handling with fewer intervening links, decreased costs for corrections, decreased phone time waiting for results
Decreased testing cost opportunities: use only the needed test
Decreased physician "mental switching" with immediate disposition of an assessment of a patient problem
|Table 3: Industry Snapshot: Point-of-Care Testing (16)|
|Table 3 is a list of advantages and disadvantages derived by the Clinical Laboratory Management Association members when asked to brainstorm POCT for a hospital-based operation:|
|Faster results||Non-lab personnel compliance|
|Better insulin management||Questionable accuracy|
|Faster treatment||Hard to manage so many personnel|
|Reduced send-out to lab||Increased cost|
|Maintain in-house clients||Loss of lab control|
|Physician perception of fast TAT||Poor documentation|
|Meets medical necessity||Process not within one department|
|Clinicians more in control of treatment||Potential loss of accreditation|
|Better clinician morale and support||Time-consuming regulatory matters|
|Improved lab image||Little capitated growth|
|Decreased lab call-in time||Financial accountability|
|Helped JACHO inspection||Training of all personnel|
|Prevents unnecessary call backs||Nursing reluctant to perform|
|Protocols allow immediate therapeutic decisions||Duplicate testing, inappropriate profile ordering|
In essence, the lesson to take away is to look at each site and application as unique. The rigor of the analysis will be dictated by the obvious great benefit or great expense identified in the situation. Again, quoting Keffer, "Although it is desirable to review published studies of the cost-effectiveness of POCT, these are typically influenced by subjective or local values and circumstances. They can not be generalized to other settings. Waiting for proof of cost-effectiveness is a failed strategy for those who want to avoid change, which will inevitably come.
All of the above aside, POCT debates inevitably focus on the microeconomic cost-analysis. Reiterating the caveat that published studies vary with respect to what costs are included or excluded, the table below is provided to offer an idea of the cost differences. It compares the laboratory cost to "some type of POCT" as described in the six references (17). What this cost-centered approach does not provide is the benefit derived from a rapid diagnostic test. Regarding the five-test chemistry panel, Tsai and coworkers found improved ER-throughput due to the ability for earlier therapeutic actions in 20% of the patients.
The cost for POCT will become more competitive as more players enter the marketplace. The price difference between the central laboratory test and the POCT will only continue to erode.
|Table 4: Ellis' Microeconomic Cost Analysis of Point-of-Care Testing|
|Glucose||Blood Gas||Chem-5 Panel|
|Lee-Lewandrowski, et al., Am J Med
|Lee-Lewandrowski, et al., Am J Med
|Winkelman, et al., (1994; 102:7-10) and
(Clin Chem 1994; 40:1628-1630)
|Greendyke, Am J Clin Pathol
|Nosanchuk, et al., Am J Clin Pathol
|Tsai, et al.,
(Clin Therap 1994; 16:898-910)
Technology has advanced to bring to the clinical laboratory new methods for analysis. This brings with it a learning curve to understand how these methods might differ from the traditional procedures and the need to educate everyone concerned as to how they should be used. In this regard, the newer methodologies utilized with the POCT equipment will bring new concepts, opportunities and, most likely, problems. An efficient quality assurance program is as necessary as any cost-efficiency analysis. It will help identify unexpected concerns and identify opportunities that a new paradigm might offer. Quality control with POCT is such an example.
For most routine laboratory tests, QC analyses check multiple steps in the testing process: reagent preparation and stability, calibration, sample and reagent delivery, mechanical systems, cuvette consistency, photometers and electronic components. The regulations of CLIA and JCAHO legally require frequent QC testing. Unfortunately, the traditional QC testing appropriate to central laboratories does not work effectively to prevent or detect most problems in POCT (18). Consequently, QC practices for POCT often become an effort to satisfy regulators and inspectors rather than to improve the quality of testing. Newer methods, like electronic QC, offer a different method more appropriate to the newer technology. The "unit-use" devise is not properly controlled with the traditional liquid control programs. More of the burden for QC will be placed with the manufac-turers in bringing their product to market by documenting the consistency of such unit-use devices. Telecommunication of patient results and operator and instrument parameters (i.e. QC values) will automatically be performed through the "box" in the very near future.
Regarding quality assurance plans, use and users will be scattered throughout the organization. The following items need to be considered with all of the applications:
|Apply a clinical perspective to the whole task; does the system meet the needs of the patient? physician?|
|Set a goal at the start of the program for analytical error that is allowable.|
|List all requirements the system needs to meet.|
|Gather information; not just internally but with other user organizations.|
|Be willing to choose/evaluate other alternatives.|
Regarding data capture, concerns have been raised regarding the issues of entering data in the medical record, recording the operator, the instrument, its QC data and recording the testing event for proper billing. Laboratory Information System (LIS) interfaces for POCT instruments have been developed (19) but are selling for close to $20,000, much higher than routine laboratory interfaces that cost around $4,000. Alternatives, like "screen-scrapers", are proposed to solve this problem.
Industry's response is envisioned to be a hand held device that communicates via cable, infrared or radio frequencies to a central data gatherer. This would allow an overseer to monitor all the Point- Of-Care Testing in an institution and coordinate programs, maintenance and troubleshooting.
The Influence of POCT on Outreach Business
The impact of POCT on outreach business for hospital laboratory systems will occur as the convenience POCT instruments make their way into the marketplace. The Intensive Care and bedside testing applications will affect inpatient testing. When will this happen? During the February 26-27, 1998 Clinical Laboratory Management Association Meeting a panel of laboratory, legal and industry "experts" presented their views regarding the progress of outreach programs across the nation. They were available to the audience for questions. When asked (20) if any of them had implemented or considered the impact of POCT on their programs, the answer was no. Apparently, the group was of the opinion that POCT was more than five years off in presenting an impact to their outreach programs. No one had done any futuring to brainstorm the impact of POCT and its potential effect to their outreach business. Obviously, no one had developed a strategy to deal with the impact such a paradigm revision would have to their market.
Today's laboratory managers struggle with reimbursement and regulatory changes for the tests their organizations perform. Consolidation, automation and group purchasing associations are methods used to cope in the current environment. POCT represents a potential influence that could dramatically affect the strategies a laboratory employs for efficiency. It presents itself at an inpatient institution as an interdepartmental challenge to perform, maintain, document and bill POCT in order to achieve some specific benefit. In an outpatient environment, it appears as a threat to outreach business.
The in vitro diagnostic (IVD) manufacturers make no secret of the fact that they are pursuing the POCT market. Indeed, they understand that outcomes research will be critical to this strategy and are active in developing not only the instruments but are designing and performing the outcome studies (21). They are investing in true clinical research to show how their products affect clinical pathways.
The future will include POCT. Certainly, during the next decade there will be a need to address how the new technologies comply with CLIA requirements. The waived category may be tailor-made for such devices. Reimbursement constraints may facilitate, not hinder, the evolution of POCT. The outpatient DRG may add fuel to the fire to move this industry along. It would place the medical necessity as well as the instrument and result in the hands of the clinician. For the laboratorian, the challenge will be to find the opportunities that these changes hold. Several authors have commented on the "future shortage of technologists" being offset with an advanced POCT industry. The opportunities will involve the knowledge and the skills these technologists have for this job.
- Bergman, M., Felig, P., Self-monitoring of blood glucose levels in diabetes. Principles and practice. Arch. Intern. Med. 1984; 144:2029-2034.
- Castro, Hector J., MD, John M. Oropello, MD, and Neil Halpern, MD; Point-of-Care Testing in the Intensive Care Unit: The Intensive Care Physician"s Perspective; Am. J. Clin. Pathol. 1995; 104 (suppl 1) S95-S99.
- Point-of-Care Testing: Pathology Patterns, Supplement American Journal of Clinical Pathology, Vol 104, No. 4 October 1995 Supplement 1.
- Brzezicki, Lisa A., The POCT Explosion, Advance for the Administrators of the Laboratory, Vol. 6 No. 2, February 1997 p.37-41.
- Arrow, Alexander, MD Point-of-Care Diagnostics Outlook, Industry Trend Report Dec. 9, 1996.
- Oberhardt, Bruce J., Patrick D. Mize and Cynthia G. Pritchard, Point-of-Care fibrinolytic tests: the other side of blood coagulation, Clinical Chemistry 43:9 1697-1702 (1997).
- Despotis, George J., J. Heinrich Joist, and Lawrence T. Goodnough; Monitoring of hemostasis in cardiac surgical patients: impact of point-of-care testing on blood loss and transfusion outcomes; Clinical Chemistry 43:9 1684-1696 (1997).
- Seamonds, B., Medical, economic and regulatory factors affecting point-of-care testing. A report of the conference on factors affecting point-of-care testing, Philadelphia, PA 6-7 May 1994; Clin Chem Acta, May 30, 1996; 249 (1-2): 1-19.
- Clinical Laboratory News, How to Make Point-of-Care Testing a Success, April 1997, p. 12-13.
- Journal of Thoracic Cardiovascular Surgery, 1994; 107:271.
- Travers, E.M., Are Federal Regulations and Managed Care Making POCT Unaffordable?, Advance for Medical Laboratory Professionals, September 8, 1997 Vol. 9, No. 18 p.12-13.
- Keffer, Joseph, Ecomonic Considerations of Point-of-Care Testing, Am. J. Clin. Pathol. 1995; 104 (Suppl 1): S107-S110.
- Weinstein, MC, Stason,WB, Foundations of cost-effectiveness analysis for health and medical practices, N Eng J Med 1977; 296: 716-721.
- Udvarhelyi IS, Colditz GA, Epstein AM; Cost-effectiveness and cost-benefit analyses in the medical literature. Ann Intern Med 1992, 116:238-244.
- Keffer JH. The economic aspects of new delivery options for diagnostic testing. In: Kost GJ, ed. Clinical Laboratory Automation Robotics and Knowledge Optimization. New York: Wiley-Interscience, 1995.
- Vantage Point, Vol. 2, No. 3 February 9, 1998 p.1.
- Jacobs, Ellis; Is Point-of-Care Testing Cost Effective?; Clinical Laboratory News, July 1996.
- Hortin, Glen L., MD, PhD, Beyond Traditional Quality Control: How to Check Costs and Quality of Point-of-Care Testing, Medical Laboratory Observer, September 1997, vol. 29, no. 9, pp. 30-37.
- Halpern, Neil; Point-of-Care: Technology and Techniques from the 62nd Annual International Scientific Assembly of the American College of Chest Physicians; October 27-31, 1996 in San Francisco, available on the Medical Association Communications web-site.
- Personal experience at the meeting.
- Auxter, Sue; Who Should be Doing Outcomes Research?, Clinical Laboratory News, March 1998, Vol 24, No. 3, p.1.