Analytic and quality control validation and assessment of field performance of a point-of-care chemistry analyzer for use in the white rhinoceros

Abstract

BACKGROUND : A chemistry point-of-care analyzer would be useful for evaluating injured wildlife, particularly white rhinoceros (Ceratotherium simum) that survive poaching attempts. The IDEXX VetTest® could be suitable, but species-specific validation, development of a statistical quality control (QC) strategy and evaluation under field conditions is necessary. OBJECTIVES : The objectives were to 1) validate the VetTest for the white rhinoceros, 2) perform QC validation on the VetTest and generate a statistical QC strategy and 3) apply this QC strategy to monitor performance under typical field conditions. METHODS : Differences between white rhinoceros heparin plasma and serum, short-term imprecision and reportable range using rhinoceros plasma and long-term imprecision using commercial quality control material (QCM) was assessed against prescribed total allowable error (TEa) for up to 15 analytes. QC validation was performed using data from the long-term imprecision study and TEa. A QC strategy using QCM was developed and used to monitor performance under field conditions. RESULTS : Imprecision was acceptable for all analytes except for ALP, ALT and AST at low activities. The reportable range for AST and LDH differed from the manufacturer’s specifications. Eleven analytes were suitable for statistical QC using the 13s rule, three using the 2s rule; ALP was not suitable. In the field, observed error was less than TEa for all fifteen analytes and the sigma metric was >3.0 for twelve analytes. CONCLUSIONS : The VetTest is suitable for use in the white rhinoceros. Statistical QC is possible for most analytes and useful for evaluation of field performance.