Evaluation of a point-of-care device for creatinine measurement in nonazotemic pigs presented to a referral hospital.

Objective: To compare creatinine concentrations measured using a point-of-care unit (Nova StatSensor; NSS) to those from a comparison method (CM) chemistry analyzer from pigs presented at a referral institution. Methods: A clinical prospective study was performed including 61 pigs admitted to Cornell Nemo Farm Animal Hospital for clinical reasons. Heparinized blood samples were obtained by venous aspiration, and whole-blood samples were obtained via ear prick. Creatinine concentrations were subsequently measured in triplicate on the NSS (on heparinized venous samples [NSSven] and ear prick samples [NSSear]) and compared to the CM. Paired t tests and intraclass correlation coefficients were performed. A Bland-Altman plot was graphed based on a linear mixed-effects model to estimate agreement between tests. Equivalence testing was performed. Results: NSSven (n = 110) and NSSear (71) from 61 nonazotemic pigs were analyzed. The mean creatinine ± SD was 1.3 ± 0.52 mg/dL from the CM, 1.1 ± 0.43 mg/dL from the NSSven, and 1.2 ± 0.42 mg/dL from the NSSear. Bias existed between average NSSven (-0.17 mg/dL) and NSSear (-0.21 mg/dL) and the CM. The 95% CI of the limit of agreement between the NSSven and CM was -0.88 to 0.54 and -1.04 to 0.62 between the NSSear and CM. The tests were not equivalent at 0.3 mg/dL. Conclusions: The NSSven, NSSear, and CM results are different and not equivalent in nonazotemic pigs. Clinical Relevance: The use of this device for screening of creatinine in pigs is discouraged based on the results in this population.