Quality assurance in urine analysis.
An Australian quality control (QC) system was tested on its ability to detect analytical errors in calcium, creatinine, oxalate, phosphate and uric acid determinations in urine. This QC system revealed that our methods for calcium and urate worked well. The oxalate values were systematically higher than the assigned values and the random error was too high. Phosphate and creatinine had a marked positive deviation in the higher range of concentration but agreed better in the medium and lower ranges. The findings emphasize the need for external QC systems in urine analysis. We also discuss specific problems with urine QC compared with conventional QC for serum, the theoretical basis of creatinine-corrected urinary analytes and criteria for rejection and warning limits. We conclude that QC of urine analysis is as important as that of serum and that such programs should be used in concordance with serum QC programs.
Larsson
L
L
Department of Clinical Chemistry, University Hospital of Linköping, Sweden.
Ohman
S
S
D001315:Australia; D002118:Calcium / Q000652:urine; D003404:Creatinine / Q000652:urine; D006801:Humans; D010070:Oxalates / Q000652:urine; D010710:Phosphates / Q000652:urine; D011785:Quality Assurance, Health Care; D011786:Quality Control; D012015:Reference Standards; D013997:Time Factors; D014527:Uric Acid / Q000652:urine; D016482:Urinalysis / Q000592:standards*
D010070:Oxalates; D010710:Phosphates; D014527:Uric Acid; D003404:Creatinine; D002118:Calcium