The study, titled “The utility of combined urine dipstick analysis and specific gravity measurement to determine feline proteinuria”, assessed the utility of the urine dipstick alone and combined with the urine-specific gravity (USG) for detecting proteinuria in cats.
For the study, the clinical records of cats presenting to a referral hospital between January 2011 and January 2017 were reviewed retrospectively.
To be eligible for inclusion, feline urine samples had to have undergone a complete urinalysis including dipstick evaluation, USG and urine protein-to-creatinine (UPC) measurement.
A total of 121 urine samples were included and diagnostic agreement and test accuracy were calculated for the dipstick test alone and in combination with the USG, using different cut-off values for proteinuria. Receiver-operating characteristic (ROC) curves were also calculated.
Jorge Pérez-Accino, corresponding author for the paper, said: “The diagnostic agreement between the urine dipstick and UPC ratio was poor and did not improve if the USG was considered together with the dipstick.
"A dipstick result of equal or greater than “Trace” (0.1-0.3g/L) had a sensitivity of 81% and a specificity of 31% to detect proteinuria.
"With regards the ROC curves, the area under the curve (AUC) of the urine dipstick alone was poor (0.57). When combined with the USG results, this improved to fair (0.78) but the specificity and negative predictive value (NPV) were still low.”
Nicola Di Girolamo, Editor of JSAP said: “These findings indicate that clinicians should not rely on the results of the urine dipstick test in combination with USG in cats for detecting proteinuria. Instead other quantitative methods, such as UPC ratio, should always be performed to detect proteinuria in cats.”
The full article can be found in the September issue of the Journal of Small Animal Practice which is free for BSAVA members. It can also be read online here: https://onlinelibrary.wiley.com/doi/10.1111/jsap.13184
The BSAVA has put together a collection of resources relating to urinalysis and proteinuria, available here: https://www.bsavalibrary.com/content/urinalysis--160
Reference
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