Planning Lab Testing for Medical Missions, Part 2

Last month I blogged about key points to consider when preparing to do lab testing in the field. Here I will expand on using point of care testing in medical missions. Point of care testing is easy to use and relatively easy to access, making it very attractive for use in the field or on medical missions. In fact, it is tempting to take these tests and go rogue – it’s not uncommon for point of care diagnostics to be obtained by non-laboratory professionals and tossed in luggage to be used by short-term medical teams. However, this is not in the best interest of the patients or the community. Helping establish point of care testing for medical missions is one very important way that a laboratory professional can get involved in this kind of outreach.

Proper utilization and quality assurance practices are just as critical in the outreach situation as at home in a large lab. Perhaps even more so; for example, in areas with high disease prevalence, false positives and negatives can significantly affect patient care and population health. Under-diagnosis due to false negatives means that those who need treatment might not get it, just as over-diagnosis due to false positives may cause patients to get unnecessary treatment. Unnecessary treatment, especially for infectious diseases, harms the community by contributing to drug resistance.

Most point of care tests, especially lateral flow tests, have built-in controls which lessens the need to run QCs with patient testing. However, it is important to know the limitations of the testing. Sometimes point of care testing systems that are not available in the United States are selected for use in outreach in foreign countries. It’s more likely that an American medical team would be unfamiliar with the tests. A laboratory professional can help establish or at least verify the validity of the tests, including limits of detection and accuracy, before they are deployed. Also, it is often helpful to have the results interpreted for the end user. Little interpretation is needed for the more straightforward qualitative tests that simply give a positive or negative result. Even with these tests, the limit of detection should be available to the provider, especially if this is significantly different from that which the provider is accustomed. Tests that involve titration, such as some of the rapid typhoid and syphilis testing, benefit from having an explanation of what the titers mean clinically available to the end user.

Other tests with results that are prone to confusion are point of care versions of assays more commonly performed in clinical laboratories. Difference in reference intervals for the POCT compared to a conventional test can be particularly confusing. For example, the results of a lateral flow point of care C-reactive protein assay have a different reference interval than results from high-sensitivity C-reactive protein assays used in clinical labs. Using the incorrect reference interval to determine whether a result is normal can lead to over- or under-treatment, which is contrary to the purpose of diagnostic testing. Yet, when using point of care tests in the field, there is not a neat little interpretive comment accompanying the result.

So, how can this be remedied? If the laboratory professional is also on the team, they can be available to provide information as needed. However, if the team is not so fortunate as to have their own laboratory professional, another way to provide the information is to provide a short guide to cheat sheet that briefly explains how to use test results.

Proper utility is also important, especially in areas with high burden of disease or in areas where there is no confirmatory testing. Consider rapid tests for H. pylori. These typically detect antibody to H. pylori, which can be found in up to 70% of asymptomatic populations. The rapid test is of little utility since positive results only indicate the presence of antibody and not necessarily an active infection. Consider using rapid screening tests, such as for HIV, when confirmatory testing is not available. Sometimes a second screening test that employs a different method than the first can be used as a confirmatory test if nothing else is available.

Consider environmental limitations of the testing when selecting tests for use in the field. Many tests are unreliable at extremes of temperature and humidity. This might not always be obvious even when quality controls are used properly. For example, Tang et al (1) showed that the effect of temperatures and humidity similar to what was experienced in Louisiana after Hurricane Katrina on quality control material for a POCT glucose meter system caused significantly depressed results. Also keep in mind that exposure to environmental extremes can reduce the shelf life of POCT and related reagents. If using POCT long term, it is good practice to routinely test a known standard – even on tests with built in quality controls such as the test line on lateral flow tests – to ensure there has not been degradation in quality due to the environment.

Preparing POCT for medical missions is a great way for a laboratory professional to get involved in global health and outreach. From helping to select appropriate tests, to verifying test validity, to teaching proper utilization of testing and providing interpretive guideline, the laboratory professional is a vital part of a medical mission – even if they never leave their lab!

  1. Tang CS, Ferguson WJ, Louie RF, Vy JH, Sumner SL, Kost GJ. Ensuring quality control of point-of-care technologies: effects of dynamic temperature and humidity stresses on glucose quality control solutions. Point of Care 2012;11:147-51.

 

Sarah Brown Headshot_small

Sarah Riley, PhD, DABCC, is an Assistant Professor of Pediatrics and Pathology and Immunology at Washington University in St. Louis School of Medicine. She is passionate about bringing the lab out of the basement and into the forefront of global health.  

CLSI Publishes New and Revised Standards on POC Testing

From the press release:

“CLSI recently released new and revised standards on point-of-care testing in relation to glucose measuring and monitoring. Effects of Different Sample Types on Glucose Measurements, 1st Edition (POCT06-Ed1), provides information to assist the clinical and point-of-care staff in result and measurement procedure comparisons of glucose tests. Glucose Monitoring in Settings Without Laboratory Support, 3rd Edition (POCT13-Ed3), focuses on performance of point-of-care glucose monitoring systems, with an emphasis on safety practices, quality control, training, and administrative responsibility.

These documents, including their sample pages, can be found on the CLSI Shop.

Microfluidics + Consumer Electronics = The Future of Point of Care Testing?

In a paper published yesterday in Science Translational Medicine, researchers tested a low-cost smartphone attachment (a “dongle”) that detects the presence of HIV and syphilis antibodies using ELIZA technology. While the research took place in Rwanda and highlights the usefulness of such technology in low-resource settings, the implications are potentially far-reaching in terms of point-of-care and direct-to-consumer testing.

What do you think? Do you think using smartphone attachments could replace full laboratories in the not-so-distant future?

Swails

Kelly Swails, MT(ASCP), is a laboratory professional, recovering microbiologist, and web editor for Lab Medicine.

Point of Care Testing Competency Assessment

Healthcare facilities can use point of care testing (POCT) devices to improve healthcare delivery. The majority of these POCT devices are waived tests, such as glucometers and hemoglobinmeters. In recent years, however, more facilities have moved toward moderate complexity testing such as troponin cardiac biomarker, blood gasses, prothrombin time, and bilirubin. Most POCT devices are operated by non-laboratory clinical personnel, such as nurses and respiratory therapists. Under CLIA regulations, these individuals are classified as testing personnel (an individual who perform laboratory testing and report test results for patient care) and must comply with competency assessment regulations.

CLIA does not have any requirement for assessing personnel competency on waived testing; however, CLIA requires that waived testing results are accurate to assist in making accurate patient diagnosis. This requires that personnel follow all manufacturer’s instructions, which generally includes personnel training, skill assessment for QC and patient testing, device maintenance and infection control procedures as the device is moved from patient to patient. When waived tests are included in the main laboratory’s CLIA license, most accrediting agencies (CAP, Joint Commission, COLA, HFAP, etc.) will also require fully established and documented personnel competency testing on all personnel who performed waived tests. It’s not uncommon for a healthcare facility to receive findings of non-compliances on POCT personnel competency assessment due to incomplete QC (both internal and external) skill assessments for each personnel. Some healthcare facilities erroneously have the laboratory POCT coordinator or supervisor perform the external QC on their POCT. All testing personnel must know how to perform all QC and their corrective action for out of control situations and documentation requirement pursuant to the organization policy.

Reference: CLIA Brochure #10.

 

Information on policies or practices are solely from my personal experience ONLY and have NO relation to my affiliation with any regulatory or government agency.

satyadi

-Caroline Satyadi, MT(ASCP), SM, DLM, SLS, MBA, MS, CQA (ASQ) has been a laboratory management professional for over 25 years. She has worked with several different medical industries for CLIA/CMS, FDA/ICH/ISO, TJC/CAP/COLA/HFAP accreditation survey readiness.