Fig. 1From: Quantifying the daily intake of water from morning and spot urine samples; retrospective analysis of a clinical trial in volunteersReceiver operating characteristic (ROC) curves that show the sensitivity and (1 – specificity) for ranges of urine osmolality in the morning urine to indicate the water consumption during the preceding day. AUC = area under the curve. The 20 volunteers delivered data on 4 consecutive days during normal fluid intake and 4 consecutive days with increased water intake. One measurement from the second period was missingBack to article page