Table 1.

Short-term storage of human urine samples before freezing of samples at 4°C or at room temperature, with either phosphoric acid added following collection or no PA added. Data shown is average (and range) percent change of the iuOTM levels as compared to the original measurement directly following collection.

Storage method	Storage duration
	1 h	3 h	6 h	24 h
4°C, PA added	106% (−23.6% to +234%)	37.1% (+3.6% to +70.6%)	44.6% (−2.7% to +91.7%)	42.1% (−41.9% to +126%)
4°C, No PA added	7.7% (−34.5% to +49.9%)	41.9% (−10.1% to +93.9%)	−30.4% (−44.7% to −16.4%)	24.7% (−17.8% to +67.1%)
RT, PA added	64.4% (−27.2% to +156 %)	50.3% (−17.5% to +118%)	17.0% (−32.5% to +66.5%)	68.8% (−27.2% to +165%)
RT, No PA added	35.6% (−25.7% to +96.9%)	13.7% (+0.1% to +27.3%)	−24.3% (−46.3% to −2.3%)	21.1% (−26.9% to +68.9%)

PA, phosphoric acid; RT, room temperature.