While the lifetime cost of UFH was lower than that of LMWH ($12,780 vs $13,001), the mean life expectancy of UFH-treated patients was also lower than that of LMWH-treated patients both in terms of unadjusted years (10.138 life-years vs 10.381 life-years) and quality-adjusted years (7.493 QALYs vs 7.677 QALYs) [Table 2]. The resulting incremental cost-effectiveness ratio was $914 per unadjusted life-year or $1,209/QALY.
In one-way sensitivity analyses (Fig 2), the incremental cost-effectiveness ratio of LMWH always remained < $3,000/QALY. Due to the lower recurrence and major bleeding rates associated with LMWH, the incremental cost-effectiveness remained < $3,000/QALY even if the early mortality with LMWH was slightly higher than with UFH (6.2% vs 6.1%). If the daily LMWH pharmacy costs were 8% of patients receiving LMWH were discharged early or if > 5% of patients were treated entirely as outpatients, LMWH use was cost-saving. If each treatment had the same early mortality, major bleeding, and recurrent VTE risks, then LMWH cost $1,360,411/ QALY. However, if the likelihood of early discharge was > 13% or if > 8% of patients were treated as outpatients, LMWH became cost-saving.