Comparative Effectiveness of New Oral Anticoagulants for ...

Comparative Effectiveness of New Oral Anticoagulants
for Thromboprophylaxis
Evidence-based Synthesis Program
RESULTS
LITERATURE SEARCH
The flow of articles through the literature search and screening process is illustrated in Figure 2.
Our search for systematic reviews (SRs) identified 162 unique citations from a combined search
of MEDLINE via PubMed (n=117), Embase (n=42), and the Cochrane Database of Systematic
Reviews (n=3). Manual searching of included study bibliographies and review articles added 20
more citations for a total of 182 unique citations. After applying inclusion and exclusion criteria
at the title-and-abstract level, 47 full-text articles were retrieved and screened. Of these, 38 were
excluded at the full-text screening stage, leaving 9 articles (representing 9 unique studies) for
data abstraction. After further review, we excluded three systematic reviews 32-34 because they
reviewed only one drug of interest and all of the primary studies included in these systematic
reviews were already represented in another, more comprehensive included review. Thus, the
final set of articles used in this evidence report comprises six systematic reviews.
Appendix B provides a complete listing of published articles excluded at the full-text screening
stage, with reasons for exclusion. We did not search www.clinicaltrials.gov for randomized
controlled trials (RCTs) currently underway, as we relied on methods in the included systematic
reviews to ascertain publication bias. We grouped the studies by key question (Figure 2).
Figure 2. Literature flow diagram
Search results:
Excluded: 135 references at the
182 references a title/abstract level
Retrieved for full-text review:
47 references
Potential for abstraction:
9 references
Excluded: 38 references
Not a systematic review: 32
Poor-quality systematic review: 1
Did not address KQs: 5
Note: 20 of these 38 were flagged
for background.
Excluded: 3 references that examined a
single drug and all primary studies were
represented in other reviews b
Abstracted:
6 systematic reviews (SRs)
KQ 1: New oral
anticoagulants
vs. comparator
(6 SRs)
KQ 2: Mechanical
interventions
(1 SR)
KQ 3: Within-class
comparisons
(2 SRs)
a
Search results for systematic reviews from PubMed (117), Embase (42), Cochrane (3), previous database (14), and manual (6)
were combined.
b
Cao, 2010; Huang, 2011; and Turun, 2011.
Note: The reference list of this report includes additional references cited for background and methods plus Web sites relevant to
the key questions.
Abbreviations: KQ=key question; SR=systematic review
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