Table 2.

Characteristics of the study population

Characteristics	n = 20
Sex, female (%)	6 (30)
Age in years, median (interquartile range, IQR)	12.7 (8.8–15.5)
Weight (kg), median (IQR)	33.9 (25.9–45.9)
Height (cm), median (IQR)	115 (136–152)
Underlying disease, n (%)
Chronic lung disease	8 (40)
Neurologic disorder	8 (40)
Immunocompromising conditiona	5 (25)
Indication for vancomycin, n (%)
Sepsis/rule-out sepsis	13 (65)
Pneumonia	4 (20)
Otherb	3 (15)
Mechanical ventilation, n (%)	11 (55)
Initial vancomycin dosing (mg/kg/day), median (IQR)	54.8 (37.4–59.4)
Initial dosing frequency, n (%)
Every 6 hours	14 (70)
Every 8 hours	6 (30)
The use of steroids, n (%)	8 (40)
Baseline creatinine (mg/dL), median (IQR)	0.4 (0.3–0.7)
Baseline cystatin C (mg/L), median (IQR)c	0.6 (0.5–0.8)
Creatinine on PK sampling day (mg/dL), median (IQR)	0.4 (0.3–0.5)
Cystatin C on PK sampling day (mg/L), median (IQR)	0.5 (0.4–0.8)
eGFR at time of PK sampling (mL/min/1.73 m2), median (IQR)
Creatinine-based equation
Schwartzbed16	138 (97–179)
Cystatin C-based equations
Schwartzcysc29	114 (87–151)
CKD-EPI32	147 (123–167)
Hoek et al.28	130 (96–177)
Grubb et al.31	163 (119–226)
Zappitelli et al.30	138 (99–197)
Creatinine and cystatin C-based equation
Full age spectrum (FAScomb)27	145 (109–175)

^aIncludes two children with a history of hematopoietic stem cell transplant, one with Crohn’s disease, one with adrenal insufficiency, and one with X-linked agammaglobulinemia.

^bIncludes one indication each for bacteremia, skin/soft tissue structure infection, and postoperative administration.

^c15 children had cystatin C data available from residual sample prior to the initiation of vancomycin and five had cystatin C data drawn following enrollment.