Assessment of a four hour delay for urine samples stored without preservatives at room temperature for urinalysis

To determine whether urine storage at room temperature for up to 2h versus 4h changes urinalysis results.

We compared the rejection rate at eight different hospital laboratories and concordance of urinalysis results (n=83; two laboratories) between urines analyzed within 2h and 4h after collection.

The rejection rate at the two hour cutoff was significantly higher as compared to the four hour cutoff. The concordance between urinalysis results was 97-100% between the two and four hour analyses.

Urine may be stored for up to 4h at room temperature without significant changes to the urinalysis results.