Rivaroxaban for the treatment of deep vein thrombosis and ...

few occasions for both VTEs and bleedings (For example 2.4% over 5,000 iterations for
VTEs).
6) There was also an error in Sheet “xxxxxxxxxxxxx. The cell was linked to the wrong cell. This
was not in favour of rivaroxaban, as part of the administration costs for LMWH were missed.
7) The analysis in the subgroup of cancer patients relies on several assumptions. Data not
specific to cancer patients were used for the risk of events once treatment cease; it is unclear
if this is appropriate. The ERG did not conduct a systematic review of the literature, but found
a study showing that the probability of readmission for VTEs within 6 months was almost
four times higher among Medicare patients with cancer than among Medicare patients
without malignancy. 76
8) The manufacturer assumed a median life expectancy of 5 years; however it is unclear if this
reflects the life expectancy of patients with a DVT.
9) It is also unclear what the risk of events in cancer patients is. The manufacturer re-used results
from the main analysis and adjusted the risk for the increased risk in cancer vs. non cancer
patients. It is unclear whether the estimate from the manufacturer reflect the baseline risk of
events.
10) The manufacturer also assumed the same baseline utility value and impact on Qol in the
general population and patients with cancer. It is likely that the baseline utility value is
different between cancer vs. non cancer patients. VTEs might also affect differently cancer
patients.
Overall, the ERG has some concerns with the accuracy of the exploratory analysis conducted by the
manufacturer in cancer patients. Whilst the ERG acknowledges that this is an exploratory analysis, the
ERG does not believe results of this analysis to be robust.
5.2.1.11. Sensitivity analysis
The manufacturer conducted a series of one-way deterministic sensitivity analyses. The probabilities
of clinical events on dual LMWH/VKA therapy and treatment effects in relation to efficacy and safety
variables for rivaroxaban vs. dual LMWH/VKA therapy were varied by using the upper and lower
95% CI values. Utility values were set at upper and lower 95% CI values or, where these were not
available, the interquartile (IQR). Resource usages were also varied in SA. Unit costs were varied by
±30% and discounting ranged between 0% to 6%. The time horizon was also varied from lifetime to 5
years. Assumptions about the monitoring were also explored varying the setting of care
(primary/secondary/hybrid). The MS also varied the mean baseline age from 46 years to 66 years.
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