Table 2.

Tacrolimus Doses and Concentrations in Nested Cohort, by Monitoring Method^a

Variable	LC-MS (n = 42)	Immunoassay (n = 61)	p d
Daily dose, mean ± S.D., mgb
All time points	6.66 ± 3.54	5.19 ± 2.71	0.03
Day of discharge–6 mo	7.19 ± 4.91	6.86 ± 3.81	0.92
6 mo–2 yr	6.25 ± 3.39	5.17 ± 2.88	0.10
>2 yr	5.35 ± 2.17	3.81 ± 2.17	0.12
Concentration, mean ± S.D., ng/mLc
All time points	8.99 ± 1.47	9.30 ± 1.33	0.21
Day of discharge–6 mo	9.49 ± 2.74	9.51 ± 1.82	0.82
6 mo–2 yr	9.24 ± 1.48	9.61 ± 1.41	0.14
>2 yr	7.64 ± 1.53	7.60 ± 1.21	0.51
Concentration:dose ratio, mean ± S.D.c
All time points	1.84 ± 1.18	2.24 ± 1.09	0.02
Day of discharge–6 mo	1.75 ± 1.02	1.85 ± 1.07	0.73
6 mo–2 yr	1.95 ± 1.18	2.36 ± 1.26	0.07
>2 yr	2.19 ± 1.89	2.43 ± 1.23	0.16

^aLC-MS = liquid chromatography–mass spectrometry.

^bMean of mean per subject daily dose.

^cTime periods are as designated by trough goal dosing protocol. Days under observation included all time points for which subjects were not receiving antifungal therapy.

^dWilcoxon–Mann–Whitney test was used to compare mean doses, trough concentrations, and concentration:dose ratios.