Table 2.

Comparison of Selected Outcomes

Parameter	2006 Standard Protocol (n = 50)	2006 Lower-Target Protocol (n = 50)	1996 Study1 (n = 50)
Primary outcomes
Time to achieve PTT > lower limit of therapeutic range (h)
Median (range)	6.0 (4.0–40.8)*	6.3 (4.5–53.0)*
Mean ± SD	8.3 ± 6.8	9.7 ± 9.2	10.7 ± 11.1
Time to achieve PTT within therapeutic range (h)
Median (range)	14.4 (4.0–40.8)†	14.3 (4.5–53.0)†
Mean ± SD	17.2 ± 12.5	16.1 ± 10.5	22.3 ± 14.0
Other outcomes
Time to first PTT measurement (h)
Median (range)	6.0 (3.0–14.3)‡	6.0 (1.8–8)‡
Mean ± SD	6.2 ± 1.6	6.0 ± 1.5	6.3 ± 1.1
Value of first PTT (s)
Median (range)	128 (53–200) 88 (43–200)
Mean ± SD	137 ± 56 106 ± 49	NA
First PTT therapeutic (no. and % of patients)	18 (36)	18 (36)	NA
First PTT subtherapeutic (no. and % of patients)	7 (14)	10 (20)	NA
First PTT supratherapeutic (no. and % of patients)	25 (50)	22 (44)	31 (62)
Value of first supratherapeutic PTT (s)
Median (range)§	200 (132–200)	150 (101–200)
Mean ± SD	188 ± 23	152 ± 37	118.9 ± 28.9
PTT within 24 h (no. and % of patients)
Patients with PTT > lower limit of therapeutic range	48 (96)	47 (94)	NA (80.9)
Patients with PTT within therapeutic range	40 (80)	40 (80)	NA
Patients with rate adjustments to therapeutic rang if initial PTT > 200 s
1 adjustment	3/16	3/6	NA
2 adjustments	7/16	3/6	NA
> 2 adjustments	6/16	0	NA

NA = not applicable or not available, PTT = partial thromboplastin time, SD = standard deviation.

^*p = 0.24, for comparison between standard and lower-target protocols.

^†p = 0.93, for comparison between standard and lower-target protocols.

^‡p = 0.94, for comparison between standard and lower-target protocols.

^§Limit of detection for PTT was 200 s; therefore, upper limit of ranges is given as 200 s, even though PTT was above 200 s for some patients.