Kovacs et al.11 compared this dosing
strategy with the 5-mg Crowther nomogram shown in
Table 130 in outpatients with venous thromboembolism. In
this comparison, the Crowther nomogram was modified
somewhat by recommending specific doses for a given INR
rather than a range of doses as was previously suggested (Tables
1 and 3). This study was the largest comparison trial and
included 201 patients. Unlike previous trials comparing different
approaches to warfarin initiation, a power analysis was
performed and the study was powered (90%) to detect a 0.5-
day difference in the time to reach a therapeutic INR. Patients
randomized to receive 10 mg (modified Kovacs nomogram)
achieved a therapeutic INR 1.4 days faster than patients receiving
5 mg (modified Crowther nomogram) (mean ± SD;
4.2 ± 1.1 vs 5.6 ± 1.4 days; p < 0.001).