James 2014.

Study characteristics
General information	Objective  Biomarkers compared Journal British Journal of Anaesthesia Country United Kingdom Study design Prospective cohort study
Participants	Number of included patients 83 Surgical specialty Noncardiac surgery Age Median 68 years (IQR = 63 to 75 years) Male sex Not reported High‐risk surgery Not reported   Insulin‐dependent diabetes mellitus Not reported History of ischaemic heart disease Not reported  History of congestive heart failure Not reported History of cerebrovascular events Not reported Elevated creatinine Not reported 0 or 1 RCRI factor 34% 2 or 3 RCRI factors 66%
Predictors	Predictor 1: ASA Objective: biomarker compared Category: patient characteristic Scale: categorical Threshold: not applicable Assay/device: not applicable   Predictor 2: BNP Objective: biomarker compared Category: blood Scale: continuous Threshold: not applicable Assay/device: Architect i2000SR, Abbott Diagnostics, USA   Predictor 3: CRP Objective: biomarker compared Category: blood Scale: continuous Threshold: not applicable Assay/device: Architect c16000, Abbott Diagnostics, USA   Predictor 4: eGFR Objective: biomarker compared Category: blood Scale: continuous Threshold: not applicable Assay/device: Roche diagnostics eGFR was calculated from age and serum creatinine with adjustment for ethnicity using the modification of diet in renal disease equation   Predictor 5: Anaerobic threshold Objective: biomarker compared Category: patient characteristics Scale: continuous Threshold: 10.6 ml/min*kg Assay/device: cardiopulmonary exercise testing   Predictor 6: Peak VO2  Objective: biomarker compared Category: patient characteristics Scale: continuous Threshold: 14 ml/min*kg Assay/device: cardiopulmonary exercise testing
Outcome	Outcome category MACE; postoperative complications Full outcome definition MACE was defined as myocardial infarction, cardiogenic pulmonary oedema, cardiac arrest or complete heart block. Postoperative complications were defined as pneumonia, wound infection, paralytic ileus, acute kidney injury, myocardial infarction, anastomotic leak, cardiogenic pulmonary oedema, haemorrhage, limb ischaemia, urinary tract infection, stroke/transient ischaemic attack, cardiac arrest, other Prediction horizon 30‐day events
Analysis	Number of outcomes 9 MACE, 40 postoperative complications    Handling missing data Complete case analysis Discrimination reported? Yes Calibration reported? No   Reclassification reported? No
PROBAST: Applicability	Domain 1: Participant selection Low Justification:  Domain 2: Predictors Unclear Justification: no information on how the RCRI predictors were defined Domain 3: Outcome Low Justification:  Overall judgement: Unclear Patient selected were generalisable to the patient population used in the RCRI development study. Outcome definitions were clearly defined/assessed and comparable to the definitions used in the RCRI development study. However, this was not the case for predictors.
Notes	—
Item	Authors' judgement	Support for judgement
Domain 1: Participant selection	No	Patients unsuitability for CPET (cardiopulmonary exercise testing) were not included.
Domain 2: Predictors	Unclear	No information on how the RCRI predictors were defined.
Domain 3: Outcome	Yes	Clearly defined outcome definitions and appropriate adjudication of outcomes.
Domain 4:  Analysis	No	Low number of outcomes and no handling of missing data; calibration and reclassification were not reported.
Overall judgement	No	Outcomes were clearly defined and assessed. However, patient selection was inappropriate, there was no/unclear information on predictor definitions and assessments. Furthermore, the number of outcomes was low and there was no information on missing data and no calibration was reported.