Fillinger 2002.

Methods	Parallel RCT Ethics committee: approved by the Dartmouth College Committee for Protection of Human Subjects (institutional review board) Informed consents: written, informed consents were obtained from all participants Site: Dartmouth‐Hitchcock Medical Center, Lebanon; and Dartmouth Medical School, Hanover, NH, USA Setting: university hospital Dates of data collection: unspecified Funding: unspecified Registration: unspecified
Participants	60 participants; mean age: 62.8 years; sex distribution: 10 females and 50 males Inclusion criteria Scheduled for elective CABG Exclusion criteria Absence of any specific contraindication to the use of heparin or warfarin anticoagulation Pre‐existing coagulopathy Infection at insertion site Septicaemia
Interventions	Intervention Epidural analgesia (N = 30) Comparator Systemic analgesia (N = 30) Premedication: fentanyl and midazolam Induction: fentanyl, midazolam, thiopental, and pancuronium or vecuronium Maintenance: isoflurane Surgery: CABG with CPB using a membrane oxygenator
Outcomes	Relevant to this review Risk of mortality Risk of myocardial infarction Risk of atrial fibrillation or atrial flutter Risk of neurological complications (cerebrovascular accidents) Tracheal extubation Pain scores Others Length of hospital stay
Notes	Correspondence: letter sent 16 March 2018; no reply Conflict of interest: not reported DOI: 10.1053/jcan.2002.29639
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "computerized randomization" (as classified by previous review authors)
Allocation concealment (selection bias)	Unclear risk	Not reported
Blinding of participants and personnel (performance bias) All outcomes	High risk	Quote: "nonblinded"
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Quote: "nonblinded" Except for ECG: recordings were reviewed by one of the study authors and a cardiologist, both of whom were blinded to treatment
Incomplete outcome data (attrition bias) All outcomes	Low risk	No loss to follow‐up
Selective reporting (reporting bias)	Low risk	All prespecified outcomes reported
Other bias	Unclear risk	Two participants in the epidural group were withdrawn from treatment in the operating room: 1 because of inability to place the catheter and 1 because of intravascular migration of an initially functioning catheter Both were included in subsequent analyses as intention‐to‐treat Groups had similar demographic data, except that 11 participants in the epidural group had a history of myocardial infarction within the 3 months immediately preceding surgery compared with 2 participants in the systemic analgesia group (P < 0.005)