Simulation models predicted that hs-cTnI results are seldom misclassified (<1% of patients) when interpretative thresholds are near or exceed the overall 99th percentile. However, simulation models also predicted that low hs-cTnI results, as recommended in guidelines, are prone to misclassification of 5%-10% of patients.
Background
In 2016, the Food and Drug Administration (FDA) proposed to enhance performance expectations for point-of-care testing (POCT) international normalized ratio (INR) devices relative to International Organization for Standardization (ISO) 17593:2007. The objective of the study was to estimate the frequency of warfarin dosing errors associated with a central laboratory INR method, a POCT INR method, and the proposed FDA performance goals.
Methods
A data set of INR results (n = 51912) from adult patients with INR ≤4 was used to assess the influence of adding assay imprecision and bias on warfarin dose decisions. The frequency of error in warfarin dose and size of error (≥1 or ≥2 dose categories) was compared using published assay specifications for the Instrumentation Laboratory ACL TOP® and the Roche Diagnostics CoaguChek® XS relative to the proposed FDA guidelines.
Results
The frequency of warfarin dose misclassification was largely influenced by bias and was not sensitive to assay imprecision. The central laboratory and POCT INR methods met the FDA performance specifications, had equal rates of ≥2 warfarin dose category error, and had statistically different rates of ≥1 warfarin dose category error in large samples (n >250).
Conclusions
Simulation models are useful tools for evaluating POCT INR assay performance criteria required to achieve the proposed FDA guidelines. This simulation depicted how the Roche Diagnostics CoaguChek XS instrument meets the guideline.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.