Patient selection: age >= 18 years of age
Hematologic complications: coagulopathy, deep vein thrombosis, major bleeding, transfusion
Parameters:
(1) surgical invasiveness index for spinal surgery (ranges from 0 to 48)
Predictors for hematological complications from multivariate analysis:
(1) age >= 40 years (odds ratio 2.0 for 41 to 64 years; odds ratio 2.3 for >= 65 years)
(2) surgical invasiveness >5 (odds ratio 2.6)
Other factors from univariate analysis:
(1) BMI > 35 kg per square meter
(2) congestive heart failure
(3) rheumatoid arthritis
(4) renal disease
(5) anemia
(6) bleeding disorder
(7) diagnosis infection or neoplasm (vs degenerative)
(8) revision surgery
(9) combined approach
