Summary Key points The “best” method of estimating glomerular filtration rate or creatinine clearance for calculation of medication doses in older adults remains elusive. Inclusion of cystatin C may enhance precision and lower bias of glomerular filtration rate estimates compared to serum creatinine alone. Clinicians may wish to use multiple equations to estimate a patient's renal function and calculate medication doses while considering the potential for adverse effects or therapeutic failure if the dose is rounded up or down based on the patient's estimated kidney function Why does this paper matter? In the absence of sufficient evidence to support or refute NKF recommendations, older adults are at risk of error estimating renal impairment and over‐ or under‐dosing medications eliminated by the kidneys.
Zarowitz et al. (Mon,) studied this question.