When initiating a 24-hour urine collection, the collection should start after a known voiding that empties the bladder. True or false?

• A. True
• B. False
• C. Cannot determine
• D. Not applicable

Answer: (A)

The main idea is to establish a clean 24-hour window for urine collection. You start by having the patient void and discard that urine so the bladder is empty, then begin collecting all urine for the next 24 hours. This ensures the total volume reflects only urine produced during the defined time period, preventing inclusion of urine from before the start or double-counting. If the bladder isn’t emptied first, the starting point is biased, which can skew results. At the end of the 24 hours, the final void is included in the collection. If a void is missed, the typical approach is to restart the collection to maintain accuracy. Therefore, starting after a known void that empties the bladder is correct.