Point-of-Care Diagnostic Testing in Global Health: What Is the Point?
Although point-of-care (POC) testing is widely considered a good idea, there is little agreement on what exactly it entails. While regulatory agencies such as the U.S. Food and Drug Administration (FDA) categorize tests based on criteria such as complexity and Clinical Laboratory Improvement Amendments (CLIA) waivers, the choice of criteria becomes vastly more complex when moving from issues concerning national to global health diagnostics. In the global health context, the dominant viewpoint
... that POC tests must meet several "ASSURED" criteria-that is, they need to be affordable, sensitive, specifıc, user friendly, rapid and robust, equipment-free, and deliverable. This dominant defınition of POC testing thus is product-oriented, and it restricts POC testing to a particular class of products: those that are inexpensive, simple, rapid (such as widely used pregnancy tests), and which health workers can use while working in the community. From this perspective, any test that needs to be conducted in a laboratory is not a POC test-creating a dichotomy between the two. We believe that this paradigm needs to be reexamined and, in doing so, propose an explicitly goal-oriented redefınition for POC testing, particularly applicable to resource-limited settings. On the basis that the rapid initiation of correct treatment is the most critical goal of any POC testing, we reverse engineered an alternative definition: POC testing is diagnostic testing that will result in a clear and actionable management decision such as when to start treatment or to require a confırmatory test, within the same clinical encounter. Why do we put rapid clinical decisions and beginning of treatment at the heart of our defınition? Quite simply, correct and timely treatment saves lives, reduces morbidity, and reduces transmission. Thus, the impact of a POC test comes from implementing effective treatments rather than from the test itself. Thus, moving rapidly through the test-and-treat cycle in the same clinical encounter is the most important goal for any POC testing program. Needless to say, this goal is what patients want-to be rapidly diagnosed and put quickly on the right treatment. Unlike the conventional, product-oriented defınition, our goal-oriented defınition for POC testing is agnostic to issues such as cost, how the test or technological platform looks, size of the product, where exactly it is performed, and who performs it. Thus, we argue that POC testing is not defıned by technology but by the successful use of a technology at the point of care to make rapid decisions. The focus must be on POC testing programs or strategies rather than technologies. SUMMARY ➤ In general, point-of-care (POC) testing refers to diagnostic products that are simple, low cost, and performed outside laboratories. This is a productcentric view of POC testing. ➤ We recommend redefining POC testing to make it goal-oriented, explicitly making the rapid initiation of correct treatment the most critical goal of any POC test. ➤ Unlike the standard definition, which creates a rigid dichotomy between POC versus laboratory tests, we suggest that POC testing should be viewed as a spectrum: of technologies (simplest to more sophisticated), users (lay persons to highly trained), and settings (homes, communities, clinics, peripheral laboratories, and hospitals). ➤ POC testing is not defined by technology but by the diagnostic process, making it important to think in terms of testing programs or strategies that lead to the rapid completion of the test-and-treat cycle. ➤ Health care systems interested in POC testing programs need to do more than purchase rapid tests; they also need to build systems for rapidly communicating test results and beginning appropriate treatments.