American Board of Internal Medicine (ABIM) Certification Practice Exam

Patients at risk for chronic kidney disease should undergo which urine test for screening?

1. Urine electrolyte analysis

2. Urine albumin excretion measurement

3. Urine pH test

4. 24-hour urine collection for creatinine

The correct answer is: Urine albumin excretion measurement

Measuring urine albumin excretion is a key component in screening for chronic kidney disease (CKD) in patients at risk. This test helps to identify the presence of albumin, a protein that should normally be reabsorbed by the kidneys. An elevated level of albumin in the urine signifies renal impairment or damage, as it indicates a disruption in the filtration process of the glomeruli, the filtering units of the kidney. Detecting increased albumin excretion early can prompt interventions that may slow the progression of kidney disease, making it a critical step in the management of at-risk patients. Other tests, such as urine electrolyte analysis or urine pH tests, do not provide the same specific information regarding kidney damage or function related to CKD. Additionally, while a 24-hour urine collection for creatinine can be used to assess kidney function, it is not as practical for routine screening as it can be cumbersome for patients and does not directly measure renal impairment like albuminuria does. Therefore, monitoring urine albumin excretion is the most effective approach for early detection and intervention in individuals at risk for chronic kidney disease.