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 are 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) were assessed against prescribed total allowable error (TE a ) for up to 15 analytes. Quality control validation was performed using data from the long-term imprecision study and TE a . 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 1 3s rule, 3 using the 2 s rule; ALP was not suitable. In the field, observed error was < TE a for all 15 analytes and the sigma metric was > 3.0 for 12 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.

Method comparison and generation of plasma biochemistry RIs for the White rhinoceros on a point‐of‐care and wet chemistry analyzer

“…Species‐specific analyzer performance was assessed based on linearity and precision experiments using rhinoceros plasma in a separate study and found to be acceptable . Bias should subsequently be calculated from method comparison to a gold standard and used to calculate TE a .…”

“…The VetTest (IDEXX Laboratories, Inc., Westbrook, ME, USA) is a chemistry POCA using dry‐slide technology that has been validated for use in the White rhinoceros in a separate publication . The Cobas Integra 400 Plus (Roche Products [Pty] Ltd., Basel, Switzerland) (hereafter referred to as the Cobas) is an automated wet chemistry analyzer utilized for routine chemistries in the clinical pathology laboratory of the Onderstepoort Veterinary Academic Hospital (OVAH).…”

“…The Cobas Integra 400 Plus (Roche Products [Pty] Ltd., Basel, Switzerland) (hereafter referred to as the Cobas) is an automated wet chemistry analyzer utilized for routine chemistries in the clinical pathology laboratory of the Onderstepoort Veterinary Academic Hospital (OVAH). Analytes for the method comparison and RI studies were selected based on their performance on the VetTest and clinical relevance and included albumin, ALT, AST, CK, creatinine, GGT, glucose, phosphorus, total protein, and urea . Reference intervals for globulins derived by subtraction of albumin from total proteins, and albumin‐to‐globulin ratio (A/G), were also calculated.…”

“…The VetTest was maintained according to the manufacturer's guidelines and daily IQC was performed using a commercial QC material (Bio‐Rad Liquid Assayed Multiqual Level 1 and 2; Bio‐Rad Laboratories Inc.) according to the protocol described in a separate study . Analyses were performed on the Cobas by trained veterinary laboratory technologists, and on the VetTest by a single trained investigator (EHH).…”

“…A point‐of‐care analyzer (POCA) would assist in evaluating these patients at the time of immobilization for treatment. A separate study describes the validation and field performance evaluation of a chemistry POCA for use in White rhinoceros . Reliable POCA RIs for healthy animals are required for interpreting results from injured White rhinoceros.…”