Smartphone-Based Colorimetric Urinalysis Evaluation

ArticleLast Updated September 20231 min read
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Leynaud V, Gillet C, Lavoué R, Concordet D, Reynolds BS. Evaluation of a smartphone-based colorimetric method for urinalysis dipstick readings in cats. J Feline Med Surg. 2023;25(5):1098612X231171434. doi:10.1177/1098612X231171434

Research Note

Visual reading of urine dipsticks is less reliable than automated analysis.1-3 This study* sought to compare diagnostic performance of a smartphone-based colorimetric method (SBCM) for urinalysis with a semiautomated point-of-care analyzer as the gold standard. Artificial solutions with fixed biochemical characteristics were used for the validation phase of the study, and almost perfect agreement between the methods was established. Optimal cutoffs were subsequently calculated, and 216 urine samples from 169 cats were tested using the SBCM and point-of-care methods. Overall agreement between the methods was 68.6%. Sensitivity, specificity, and accuracy were 100%, 76%, and 80.5%, respectively, for the SBCM. Specificity for bilirubin and proteinuria was low. The authors concluded the SBCM showed acceptable overall agreement with the chosen gold standard, but positive results for bilirubin and protein should be cautiously interpreted and confirmed using a different testing method. 

*This study was supported in part by Nov&Sat SAS.