The probable connection between patient safety and point-of-care testing appears at the intersection of technical limitations, rapid availability, and the therapeutic implications of this genre of tests [1]. In the absence of a systematic evidence base, a series of definitions may be used to approach the topic. (These include definitions of patient safety, medical error, and preventable adverse event, as well as definitions of point-of-care testing itself and point-of-care test operator; and the stipulations of three regulatory categories: waived testing, provider-performed microscopy testing, and moderate complexity testing.) The eight definitions collide with actual point-of-care testing practice to reveal latent conditions that predispose point-of-care test systems to active medical errors [2-4]. These latent conditions appear with special prominence among tests in the regulatory category of waived point-of-care testing [5]. The medical consequences of these limitations require more attention, both to detect point-of-care testing errors and to prevent the adverse events that flow from them [6-10]. A modified version of Kost's taxonomy of potential defects in the point-of-care testing process exposes the conditions conducive to error that are implicit in this kind of assay [11, 12]. The taxonomy provides a framework for detecting where errors arise in the process, so the relative frequencies of different errors may be measured. It also permits measurement of the frequency with which various types of errors progress to preventable adverse events [ 13]. Systematic investigations of the "connectivity" between point-of-care testing error and preventable adverse events need to be performed. The authors suggest some topics for this research agenda. The authors conclude by outlining the existing point-of-testing laboratory ethos, embodied in the standard model of safe laboratory testing [14]. Adherence to this ethos encourages a "culture of safety" in point-of-care testing by (1) advancing operator competency, procedural consistency, quality control, and result integrity and (2) monitoring patient identification, specimen adequacy, and report accuracy [15,16].
