The nurse plans to collect a 24-hour urine specimen for a creatinine clearance test. Which instruction should the nurse provide to the CLIENT?

A. This instruction is incorrect because it suggests collecting catheterized specimens, which is not necessary for a creatinine clearance test. Catheterization may increase the risk of contamination and is not typically performed for this test. B. This instruction is incorrect because it does not involve the collection of a complete 24-hour urine specimen. Collecting specimens every 6 hours would not provide an accurate measurement of creatinine clearance over a 24-hour period. C. This instruction is correct. For a 24-hour urine collection, the client should urinate at a specified time to start the collection period, discard this urine, and then collect all subsequent urine produced over the next 24 hours. This ensures that the entire 24-hour period is captured for analysis. D. This instruction is incorrect because it does not involve the collection of all urine produced over a 24-hour period. Additionally, discarding the first portion of voiding is not necessary for a creatinine clearance test and may lead to inaccurate results.