Assessment of a four hour delay for urine samples stored without preservatives at room temperature for urinalysis.
Author(s): Veljkovic K, Rodríguez-Capote K, Bhayana V, Pickersgill R, Beattie J, Clark L, Kavsak PA
Publication: Clin Biochem, 2012, Vol. 45, Page 856-8
PubMed ID: 22548911 PubMed Review Paper? No
Purpose of Paper
This paper investigated the effects of storing specimens at room temperature for 4 h rather than 2 h on the results of chemical and microscopy analysis of urine.
Conclusion of Paper
Greater than 97% concordance in results was achieved between specimens analyzed within 2 h and 4 h for all analytes and complete agreement of results was obtained in 54% or greater in all specimens.
Studies
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Study Purpose
This study investigated the effects of storing specimens at room temperature for 4 h rather than 2 h on the results of chemical and microscopy analysis of urine. Levels of nitrites, glucose, leukocyte esterase, hemoglobin, proteins, ketones, specific gravity, pH, epithelial cells, erythrocytes, bacteria, and leukocytes were determined in 83 specimens after 2 h at room temperature and again after 4 h. Concordance was defined as results within one color block from the best-fit analysis or within one reporting range. Agreement was defined as both results on the best-fit line.
Summary of Findings:
Concordance of glucose, leukocytes esterase, hemoglobin, proteins, and epithelial cell counts was 100% between specimens analyzed within 2 h and after 4 h. Further, 99% concordance for ketones and specific gravity, 98% for pH, and 97% for erythrocytes, bacteria, and leukocyte counts was observed for specimens analyzed after 2 and 4 h, respectively. Importantly, complete agreement of results was obtained in 54% of specimens for pH, 76% of specimens for specific gravity, 77% of specimens for leukocyte counts, 86% of specimens for proteins, 87% of specimens for epithelial cell counts, 88% of specimens for hemoglobin, 90% of specimens for bacterial counts, 91% of specimens for leukocyte esterase, 93% of specimens for ketones and erythrocyte counts, 99% of specimens for glucose, and 100% of specimens for nitrites.
Biospecimens
Preservative Types
- None (Fresh)
Diagnoses:
- Not specified
Platform:
Analyte Technology Platform Carbohydrate Clinical chemistry/auto analyzer Cell count/volume Light microscopy Small molecule Clinical chemistry/auto analyzer Protein Clinical chemistry/auto analyzer Electrolyte/Metal Clinical chemistry/auto analyzer Pre-analytical Factors:
Classification Pre-analytical Factor Value(s) Storage Time at room temperature 2 h
4 h