Which statement correctly describes the two commonly used equations to estimate GFR in adults?

• A. CKD-EPI and MDRD are the two commonly used equations to estimate GFR in adults.
• B. MDRD is used for pediatrics; CKD-EPI for adults only.
• C. Cockcroft-Gault and Schwartz are standard for adults.
• D. Jaffe equation estimates GFR.

Answer: (A)

Estimating GFR in adults relies on creatinine-based equations that convert a single serum creatinine measurement into a filtration rate, accounting for factors that affect creatinine production and clearance. The two most commonly used are CKD-EPI and MDRD. The MDRD formula was developed in patients with CKD and uses serum creatinine, age, sex, and race to estimate GFR, performing well at lower GFR but less accurate at higher values. The CKD-EPI equation was designed to improve accuracy across a wider range of GFR, particularly above 60 mL/min/1.73 m^2, and it uses the same types of variables. In practice, these two are the standard tools for estimating GFR in adults.

Cockcroft-Gault estimates creatinine clearance and includes body weight, which is related but not the same as GFR. Schwartz is used for pediatric patients. The Jaffe equation refers to a method of measuring creatinine concentration, not to an equation for estimating GFR.