Table 1.

Population demographics of infants used in model development

Population characteristic	Prophylaxis study18	PPRU study12	Infants with CSF dataa
Number of infants	120	46	22
Number of samples	489b	298c	27
Number of doses	11 (1–13)	7 (1–61)	12 (1–13)
Dose, mg/kgd	6.0 (2.8–8.1)	2.9 (0.8–12.5)	5.9 (1.9–7.3)
Actual dose, mgd	4.3 (1.9–18.0)	4.2 (1.4–85.0)	4.6 (2.8–9.0)
Dosing frequency, hr	89 (0–433)	24 (0–272)	73 (0–167)
Gestational age, weeks	24.9 (22.6–28.7)	26.0 (24.0–40.0)	25.5 (22.6–37.0)
Postnatal age,e days	19.0 (3.0–46.0)	21.0 (2.0–93.0)	18.0 (7.0–50.0)
Postmenstrual age,e weeks	27.6 (23.7–35.1)	30.0 (24.7–49.6)	27.9 (23.7–33.1)
Weight,e g	720 (345–2680)	1155 (451–7138)	780 (490–2350)
Serum creatinine, mg/dL	0.8 (0.1–2.0)	0.4 (0.1–1.9)	0.7 (0.2–2.0)
Sex, %
Male	36.7	54.3	45.5
Unknown/not reported	0	6.5	0
Ethnicity,f %
Not Hispanic or Latino	86.7	82.6	81.8
Hispanic or Latino	13.3	8.7	18.2
Unknown/not reported	0	8.7	0
Race,f %
White or Caucasian	40.0	47.8	45.4
Black or African American	52.5	37.0	45.5
American Indian or Alaska native	5.8	0	9.1
Asian	1.7	4.3	0
Native Hawaiian/other Pacific Islander	0	2.2	0
More than one race	0	0	0
Unknown/not reported	0	8.7	0

Data reported as median (range) for continuous variables.

CSF, cerebrospinal fluid; PPRU, Pediatric Pharmacology Research Unit.

^aPreviously unpublished data. ^bOf the 489 samples used in model development, 464 were plasma samples, and 25 were CSF samples. Oral samples from this study were excluded from analysis. ^cOf the 298 samples used in model development, 296 were plasma samples, and 2 were CSF samples. ^dMedian (range) was calculated across all administered doses. ^eMedian (range) was calculated across all sample records. ^fFor the prophylaxis study, the maternal ethnicity and race were recorded.