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

Table 8: Quality assessment of EINSTEIN-DVT and EINSTEIN-Ext as reported in MS
(Table 17, page 53).
Was randomisation carried out
appropriately?
Was the concealment of treatment
allocation adequate?
Were the groups similar at the outset of
the study in terms of prognostic factors?
Were the care providers, participants and
outcome assessors blind to treatment
allocation?
Were there any unexpected imbalances in
drop-outs between groups?
Is there any evidence to suggest that the
authors measured more outcomes than
they reported?
Did the analysis include an intention-totreat
analysis? If so, was this appropriate
and were appropriate methods used to
account for missing data?
4.1.5 Evidence synthesis
41
EINSTEIN-DVT EINSTEIN-Ext
Yes Yes
N/A Yes
Yes Yes
Investigators & Patients were not
blinded to treatment. Outcome
assessors were blinded to
treatment allocation.
Yes, all groups were
blinded to treatment
allocation.
No No
No No
Yes Yes
No evidence synthesis was performed for the direct evidence review, due to incompatibility of the
study evidence in terms of comparators and study populations. This was considered appropriate by the
ERG.
4.2 Critique of trials of the technology of interest, their analysis and interpretation (and any
standard meta-analyses of these)
The MS clinical effectiveness review identified 6 rivaroxaban studies, only four of which are
published. 21,35,36 All six are listed in Table 9. Only four studies 21,35,36 met all of the inclusion criteria,
as the CYP cohort study (Page 31, MS) was a single arm study, and the EINSTEIN PE (Page 31, MS)
study did not select a population with symptomatic DVT. Of the four studies that met the inclusion
criteria, two 35,36 were described in detail, but essentially excluded from further analysis because they
were phase II, proof of concept, dose-ranging studies. The ERG agrees that it is appropriate not to
focus on these studies for the previously mentioned reasons, and because:
Neither study used the licensed doses across the whole treatment period;
o ODIXa-DVT 35 used 10mg bid or 20 mg bid, but not 15mg bid, and
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