Fig 1.
PRISMA flowchart of studies included in the final synthesis of the systematic review.
Fig 2.
An outline of the stages of the ESC-DAG protocol [11], including an example construction of a perioperative DAG.
Fig 3.
Stages, purpose, and the steps of DAG construction outlined in the ESC-DAG protocol [11] that the reviewers scored the final papers against.
IG: implied graph (a DAG that acts as a structural template to build the DAG).
Table 1.
Process followed by the authors to collect the data and score the DAGs in the studies against the ESC-DAG protocol [11].
Table 2.
Table depicting the year, journal, study objective and publication date relative to the ESC-DAG protocol of the final nineteen studies.
Whether the DAG within the study included a temporal variable is also recorded. A study including temporal variables means this study acknowledged or specified that a certain variable e.g., drug usage was measured at a specific time point in the preoperative pathway.
Table 3.
Table demonstrating the results from the screening of all nineteen papers when assessed against the ESC-DAG protocol [11].
Table 4.
Table demonstrating the extent to which different studies dealt with unmeasured variables, if at all.