Utility of estimated glomerular filtration rate using cystatin C and its interpretation in patients with rheumatoid arthritis under glucocorticoid therapy

eGFRcys of patients taking a daily PSL dose ≥10 mg was inaccurate, while eGFRcys was underestimated. eGFRcys was more accurate than eGFRcreat or eGFRavg for patients taking a daily PSL dose of <10 mg.