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

Figure 1 Flow diagram for identifying RCTs (reproduced from Figure 2 ‘Study flow
diagram for the identification of references relating to RCTs’ in the MS, page 31) 1
MEDLINE n=116 EMBASE n=535
The MS stated that 687 records were identified from the conducted searches; of these, one
record was obtained from ‘non-literature database sources’. It is unclear what this source was,
as this does not appear to have been defined in the MS, and is also not reflected in the flow
diagram.
Potentially relevant records
(titles/abstracts) screened n=687
Relevant RCTs identified n=4
Although, the MS explained that 687 of the records retrieved were excluded, the ERG
assumed that this was minor typo error as the flow diagram indicated that the number of
records excluded was 683. This was confirmed by the manufacturer. 17
The study selection process lacked transparency. Details on number of duplicates, number of
studies excluded at title and abstract stage and number of full text papers screened for
possible inclusion were missing. Though the manufacturer stated that, ‘Where studies were
published as abstracts then subsequently as full papers, the abstracts were excluded’, it is
unclear at what stage this decision was made. Lack of clarity in this case introduces the
potential for bias in the review; linking the two publications and documenting that decision
would have been a more acceptable approach. However, the ERG does not feel this is likely
to have introduced bias to the review in this case.
36
CENTRAL n=36
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Records excluded n=683
Most were duplicates,
review/editorials articles, non-
English language publications
related to included RCTs or
concerning orthopaedic or non-
VTE indications.