Quality of evidence
Through our risk of bias assessment of the included studies, we
determined that evidence of the 2 randomized controlled trials were of
robust quality, with no severe risk of bias associated with the design
of the studies12,13 (Figure 2). For the observational
studies14-17, apart from high risk of bias in
confounding factors and patient selection that are typical of studies
with retrospective nature, we determined that the evidence provided by
these studies (and the included studies overall) was still of an
acceptable quality (Table 1).
Of the 6 included studies, 2 were randomised control
trials12,13 and 4 observational
studies14-17. In 2 of the observational
studies16,17 included were only participants who
underwent FFR-guided CABG (single-arm studies). The data from these
studies was used to carry out a pooled analysis.