CST3 and chronic kidney disease: Using an eGFR < 60 ml/min/1.73m2 cut-off, the highest prevalence was with the Schwartz cystatin C equation which showed a 1.4%; 95% CI: 0.5–2.9% prevalence of kidney impairment and a 0.8%; 95% CI: 0.2–2.1% prevalence of CKD at the 3-month follow-up.