Clinical application of the StatSensor and StatSensor Xpress point-of-care creatinine measurement devices in dogs

Creatinine is a universally important blood parameter used to detect and monitor acute and chronic kidney disease. Reliable measurements at the bedside remain a challenge in human and veterinary medicine. Despite its potential, a trustworthy point-of-care creatinine biosensor has yet to be established.

We aimed to determine the precision and accuracy of the StatSensor (SS) and StatSensor Xpress (SSX) handheld creatinine measurement devices in dogs.

Paired creatinine samples from dogs with normal (creatinine ≤159 μmol/L), moderate (159-354 μmol/L), and marked (>354 μmol/L) azotemia were compared with a commercial enzymatic analyzer. Within-day precision and linearity studies were performed prior to method comparison studies. Method comparison was evaluated using Bland-Altman, concordance correlation coefficient, Deming, and Passing-Bablok regression analysis.

Seventy-eight dogs were enrolled in the study, including 28 (35%), 25 (32%), and 26 (33%) with normal, moderate, and marked azotemia. Total error surpassed recommendations for all devices, and linearity deviated from identity for the SS1 and SS2. The concordance correlation coefficients of the SS1, SS2, SSXI, and SSX2, were 0.69, 0.59, 0.82, and 0.44, respectively. Bland-Altman analyses showed a high variation in the differences, and relationships showed high heteroskedasticity with negative systemic bias among high creatinine concentrations.

Neither the SS and SSX are considered acceptable for clinical applications in dogs. Further research is indicated for the development of a reliable, cost-effective, point-of-care creatinine analyzer to improve the rapid detection and monitoring human and veterinary patients.