Point-of-Care Testing and Quality Control

June 2018 - Vol.7 No. 5 - Page #10

Q&A with Eugenio H. Zabaleta, PhD
OhioHealth Mansfield Hospital
Mansfield, Ohio

The initial part of this discussion, POCT and the Chemistry Lab, appeared in the April 2017 issue of Medical Lab Management. Visit medlabmag.com/article/1369 to review.

MedicalLab Management: What do administrators, physicians, nurses, and other non-laboratory clinicians who request or perform point-of-care testing (POCT) need to know about the capabilities of this testing?

Eugenio H. Zabaleta: When it comes to POC testing and diagnostics, all clinicians and users should understand the following:

  • All devices have limitations
  • Errors are usually operator related
  • There are conditions under which the device will fail
  • When a device produces a result, that does not automatically mean the result is correct
  • The specific risks and limitations for the test/device they are using/requesting (emphasizing the concept that clinical laboratories should incorporate POC device quality control actions into user training to instill the integral and comprehensive idea of that test’s risk management/mitigation)
  • Clinicians should always use their best clinical judgment to verify the validity of the result in the clinical context of the patient disease/process, not only for POCT, but for all testing

MLM: What quality control mechanisms can be implemented in the POCT process?

Zabaleta: An individualized quality control plan (IQCP) can be applied to any POCT instrument. However, to understand how the IQCP concept was developed and why, it is important to understand the background of POCT quality control. Until January 2016, there were two options for nonwaived POCT: run two levels of external QC per day (of patient testing) or have an equivalent quality control (EQC) option in place. EQC was introduced by CLIA in 2004 to simplify QC for laboratory tests/systems that include an internal monitoring system and are considered stable in both environmental conditions and operator handling. Under EQC, laboratories were allowed to perform external QC less frequently than every day (eg, once a week or once a month), as long as the frequency remained within the manufactures’ specifications, the device had an internal control, and was considered stable to external factor changes.

In 2011, the Clinical & Laboratory Standards Institute (CLSI) published its EP-23 document and formally introduced the IQCP, effectively replacing the EQC process. EP-23 was subsequently adopted (ie, enforced) by CMS in January 2016. In summary, today the laboratory has two options: Use an IQCP or run two levels of external QC per day (of patient testing).

MLM: How do you explain the difference between the EQC and IQCP processes to POCT staff who are not laboratorians?

Zabaleta: EQC was an effort to simplify QC for certain POCT, such as robust performance regardless of environmental changes or operator handling, plus the device has a built-in monitoring system. The issue with the EQC process is that it focused on device performance only (ie, the analytical phase). Thus, the IQCP approach was designed to be more comprehensive and proactive than the EQC approach. In explaining this to non-laboratory-educated staff the clinical champion and/or appropriate laboratory personnel should emphasize the following points:

  1. The laboratory should perform a risk assessment that encompasses all phases of the testing process (pre-analytical, analytical, and post-analytical)
  2. The laboratory should develop a IQCP that includes all the practices, procedures, and recourses to maintain quality (eg, electronic/internal controls, proficiency testing [PT], calibration, maintenance, training, competency assessment)
  3. The laboratory should have a quality assessment (QA) program to constantly monitor the effectiveness of the IQCP (eg, specimen rejection logs, QC reviews, PT performance reviews, chart reviews, TAT reports, physician/clinician feedback)

The IQCP then becomes a living document used to teach non-laboratorians (who are performing nonwaived POCT) all relevant factors that affect testing, how to control them, and how important it is to frame the result within the individual patient’s clinical picture. This last part is vital as the ultimate dedication to “do no harm” to patients. As with any diagnostic test, the production of a result does not guaranty its quality.

MLM: How does IQCP impact non-laboratorians performing POCT?

Zabaleta: The application of an IQCP will impact every staff member performing POCT regardless of whether they are medical technologists, nurses, or physicians. Keep in mind that an IQCP is not just a document prepared once and then forgotten about. Rather, it remains a living document that requires review at least annually. The laboratory needs to reassess the risk to ensure that QC can still be run in intervals less frequently than two levels of QC per day of patient testing, but not exceeding manufacturer specification. If the risk is too high because of error or changes in the package insert, FDA reclassification, etc, then the performance of QC needs to change. If risk is determined to be high, QC should be performed every day that patient testing is performed in order to assure the quality of the results. This is a patient safety issue.

Consider the use of glucose meters on the unit; because the meters are often used by many different operators during the course of a day, it is safer to perform two levels of QC every day the meter is used. So, in my hospital, the meters are programmed to ask for external QC every 24 hours to be continually useable.

MLM: What are the IQCP criteria that should be evaluated every year?

Zabaleta: A good annual review should include the following points (as they apply to a specific laboratory operation):

  • Internal and external control performance and documentation
  • Proficiency testing survey results
  • Vendor recall data
  • Package inserts (monitor updates)
  • Training and competency records of new operators
  • Annual competency records of all operators
  • Related temperature records
  • Instrument maintenance records
  • Error logs and/or amended results
  • Physicians complaints/risk management form

MLM: If it is determined that QC should be performed at two levels every day for POCT instruments based on a risk assessment, how can the laboratory maintain control of the process?

Zabaleta: Many POCT devices can be configured to require a forced function when external QC should be performed (as determined by the laboratory medical director). If external QC is not performed within a predetermined time frame, the device will lock until two levels of QC are performed and the instrument passes the required QC. This is the case of our glucose meters used by nursing.

MLM: How can laboratory management specify QC for a specific POCT discipline such as hematology?

Zabaleta: It may be best to view POCT is a discipline in itself. When the topic is nonwaived POCT devices, it does not matter what core lab discipline is in question (especially if the testing is performed by non-laboratory personnel). The QC plan is simply part of the overall IQCP specific to a specific test system’s risk assessment.

Inversely, if we are discussing hematology testing (complete blood count [CBC]) performed by a POCT device, specifically, my biggest point of concern (and that of my medical director) would not be about the QC plan (although that was an important aspect); rather, we would consider the greatest risk involved production of the result itself, according to our individual validation results and risk assessment (ie, the IQCP).

To be more specific, currently available POCT devices can perform a CBC that contains 13, 18, 22, or even 26 parameters (ie, individuals’ results). Further, some devices perform three-part differentials, whereas others can perform five-part differentials. As such, a single device is performing several different measurements and calculations, each one with its own limitations and error risk.

Thus, my primary advice for clinical laboratories seeking to implement a new CBC POCT device is to include in the validation study several patients with hematological abnormalities covering as many cell lines as possible. The idea is to see what range of results are produced and gain clinical experience with the device. If there are no medical technologists available to perform a manual CBC differential on location, the questions remain: How are you going to manage these results and do what is the best for your patient population? Is the solution to result every test that produces a value within the analytical measurement range (AMR) and then add a comment suggesting samples that do not fall in this range be sent to the central lab for a manual review? Will additional restrictions be added?

In addition, is it reasonable to send to the EMR a result that does not contain any or few results from one cell line? Will the laboratory charge for an incomplete CBC test?

MLM: How can these questions be applied to error review of CBC testing instruments?

Zabaleta: In our case, we wanted to exercise great caution in ensuring the safety of our patients. After we studied the package insert for our hematology POCT devices for the manufacturer’s specifications, and after we performed our validation studies and IQCP, the next logical step was to stratify the error codes we encountered.

For example, when we obtain any error in which the manufacturer recommends a smear review, we suppress all the results and we issue a result with the following comment: Possible interfering substances and/or clinically significant abnormalities that require smear review. Recommend re-draw and reordering as CBC w/Diff, and send to the core laboratory. It is important to mention when this happens, we do not charge the patient for the point-of-care CBC test because we are not providing results.

For more information on IQCP processes, please review the following past articles in MedicalLab Management:

Eugenio H. Zabaleta, PhD, is a clinical chemist at OhioHealth Mansfield Hospital in Mansfield, Ohio. He is also a part-time lecturer at Cleveland State University’s graduate clinical chemistry program. He graduated from the Catholic University of Cordoba (Argentina) with a degree in biochemistry and received his PhD in chemistry from the University of Akron. His training in clinical pathology was at the Hospital Provincial San Roque in Cordoba. In Argentina, he was the laboratory medical director at the Clinica del Sol, a clinic devoted to mother and child’s care, with neonatology intensive care service.


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