Urine for a urinalysis can be collected at any time. A sufficient sample is required for accurate results. Participants were asked to bring in one of the following urine samples to 1A visit 2:

First morning samples are the most concentrated and the most likely to detect abnormalities. Participants were instructed as follows:

• empty your bladder before lying down to sleep
• do not urinate during the night
• collect one to two ounces of the first urine from the first urination in the morning in a clean container
• keep the urine specimen cold
• bring the specimen to 1A Visit 2.