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

6.5. Exploratory analysis in cancer patients – examining different HR
The ERG explored 3 scenarios, using the mean HR/OR assuming a between study variability of
U(0,5), U(0,2) and U(U,0.6).
In addition to the above, the ERG corrected the following errors:
- xxxxxxxxxxxxxxxxxx, the cell was linked to the wrong cell cccccccccccc).
- Finally, an error is corrected for the probability of PE recurrences (xxxxxxxxxxxxx4) after the
first year (which had been incorrectly divided by 4).
Results are presented for the deterministic sensitivity analysis as there were issues with the PSA. A
summary of the analyses undertaken by the ERG are provided in Table 57.
The ERG believes these results to be exploratory rather than definitive due to the caveats listed below.
The main uncertainties within the analyses relate to:
- The baseline risk of events – it was necessary for the manufacturer to make a series of
assumptions to represent the risk of events, and it is unclear to what extent this reflect the risk
of events in the cancer population,
- The treatment effect was taken from the MTC, however there were considerable uncertainty
in the relative treatment effects,
- 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.
- The manufacturer assumed a median life expectancy of 5 years, however it is unclear if this
reflect the life expectancy of patients with a DVT.
- 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. The impact of VTEs in cancer patients may
also be different.
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