The results of analyte enhancement and use of supplied urine protein standard on the CAP Urine Chemistry Survey Program.

Thirteen analytes were presented for participant analysis during the year 1979. Included were amylase, calcium, phosphorus, sodium, potassium, creatinine, osmolality, total protein, glucose, urea nitrogen, 17-ketosteroids, 17-ketogenic steroids, and vanillylmandelic acid. A urine protein standard was provided, and approximately half of participating labs used it. The severe biases demonstrated in past years between urine protein analytic methods was eliminated, and interlaboratory precision was greatly improved. Among labs not choosing to use the standard, poor interlaboratory precision and severe bias between methods persisted. Elevation of sodium and calcium concentration to levels simulating human disease resulted in significantly poorer analytic performance.