Preoperative prediction of Bleeding Independently associated with Mortality after noncardiac Surgery (BIMS): an international prospective cohort study.

BACKGROUND: Diagnostic criteria for Bleeding Independently associated with Mortality after noncardiac Surgery (BIMS) have been defined as bleeding that leads to a postoperative haemoglobin <70 g L-1, leads to blood transfusion, or is judged to be the direct cause of death. Preoperative prediction guides for BIMS can facilitate informed consent and planning of perioperative care. METHODS: In a prospective cohort study of 16 079 participants aged ≥45 yr having inpatient noncardiac surgery at 12 academic hospitals in eight countries between 2007 and 2011, 17.3% (2782) experienced BIMS. An electronic risk calculator for BIMS was developed and internally validated by logistic regression with bootstrapping, and further simplified to a risk index. Decision curve analysis assessed the potential utility of each prediction guide compared with a strategy of identifying risk of BIMS based on preoperative haemoglobin <120 g L-1. RESULTS: With information about the type of surgery, preoperative haemoglobin, age, sex, functional status, kidney function, history of high-risk coronary artery disease, and active cancer, the risk calculator accurately predicted BIMS (bias-corrected C-statistic, 0.84; 95% confidence interval, 0.837-0.852). A simplified index based on preoperative haemoglobin <120 g L-1, open surgery, and high-risk surgery also predicted BIMS, but less accurately (C-statistic, 0.787; 95% confidence interval, 0.779-0.796). Both prediction guides could improve decision making compared with knowledge of haemoglobin <120 g L-1 alone. CONCLUSIONS: BIMS, defined as bleeding that leads to a postoperative haemoglobin <70 g L-1, leads to blood transfusion, or that is judged to be the direct cause of death, can be predicted by a simple risk index before surgery. CLINICAL TRIAL REGISTRATION: NCT00512109.

Bleeding Independently associated with Mortality after noncardiac Surgery (BIMS): an international prospective cohort study establishing diagnostic criteria and prognostic importance.

BACKGROUND: We aimed to establish diagnostic criteria for bleeding independently associated with mortality after noncardiac surgery (BIMS) defined as bleeding during or within 30 days after noncardiac surgery that is independently associated with mortality within 30 days of surgery, and to estimate the proportion of 30-day postoperative mortality potentially attributable to BIMS. METHODS: This was a prospective cohort study of participants ≥45 yr old having inpatient noncardiac surgery at 12 academic hospitals in eight countries between 2007 and 2011. Cox proportional hazards models evaluated the adjusted relationship between candidate diagnostic criteria for BIMS and all-cause mortality within 30 days of surgery. RESULTS: Of 16 079 participants, 2.0% (315) died and 36.1% (5810) met predefined screening criteria for bleeding. Based on independent association with 30-day mortality, BIMS was identified as bleeding leading to a postoperative haemoglobin <70 g L-1, transfusion of ≥1 unit of red blood cells, or that was judged to be the cause of death. Bleeding independently associated with mortality after noncardiac surgery occurred in 17.3% of patients (2782). Death occurred in 5.8% of patients with BIMS (161/2782), 1.3% (39/3028) who met bleeding screening criteria but not BIMS criteria, and 1.1% (115/10 269) without bleeding. BIMS was associated with mortality (adjusted hazard ratio: 1.87; 95% confidence interval: 1.42-2.47). We estimated the proportion of 30-day postoperative deaths potentially attributable to BIMS to be 20.1-31.9%. CONCLUSIONS: Bleeding independently associated with mortality after noncardiac surgery (BIMS), defined as bleeding that leads to a postoperative haemoglobin <70 g L-1, blood transfusion, or that is judged to be the cause of death, is common and may account for a quarter of deaths after noncardiac surgery. CLINICAL TRIAL REGISTRATION: NCT00512109.

Bleeding impacting mortality after noncardiac surgery: a protocol to establish diagnostic criteria, estimate prognostic importance, and develop and validate a prediction guide in an international prospective cohort study.

INTRODUCTION: Various definitions of bleeding have been used in perioperative studies without systematic assessment of the diagnostic criteria for their independent association with outcomes important to patients. Our proposed definition of bleeding impacting mortality after noncardiac surgery (BIMS) is bleeding that is independently associated with death during or within 30 days after noncardiac surgery. We describe our analysis plan to sequentially 1) establish the diagnostic criteria for BIMS, 2) estimate the independent contribution of BIMS to 30-day mortality and 3) develop and internally validate a clinical prediction guide to estimate patient-specific risk of BIMS. METHODS: In the Vascular Events In Noncardiac Surgery Patients Cohort Evaluation (VISION) study, we prospectively collected bleeding data for 16 079 patients aged 45 years or more who had noncardiac inpatient surgery between 2007 and 2011 at 12 centres in 8 countries across 5 continents. We will include bleeding features independently associated with 30-day mortality in the diagnostic criteria for BIMS. Candidate features will include the need for reoperation due to bleeding, the number of units of erythrocytes transfused, the lowest postoperative hemoglobin concentration, and the absolute and relative decrements in hemoglobin concentration from the preoperative value. We will then estimate the incidence of BIMS and its independent association with 30-day mortality. Last, we will construct and internally validate a clinical prediction guide for BIMS. INTERPRETATION: This study will address an important gap in our knowledge about perioperative bleeding, with implications for the 200 million patients who undergo noncardiac surgery globally every year. Trial registration: ClinicalTrials.gov, no NCT00512109.