Background: Current medical practice urges individual health care facilities and medical professionals to obtain and provide detailed insight in quality of care with the possibility of comparing data between institutions. Adverse event (AE) analysis serves as a mainstay in quality assessment in vascular surgery, but the comparison of AE data between facilities can be complex. The aim of the present study was to assess independent risk factors for AE occurrence: patient, disease and operation characteristics besides general differences between health care facilities. Methods: All AEs after infrainguinal bypass graft procedures (BGPs) in three health care facilities in the Netherlands were evaluated. AEs were defined identically in the facilities. Results: Of 601 BGPs performed, 662 AEs were registered. Independent predictors of AEs were female gender (odds ratio [OR], 2.13; 95% confidence interval [CI], 1.39-3.26; P < .01), age ≥60 years (OR, 0.57; 95% CI, 0.34-0.95; P = .03), American Society of Anesthesiologists classification 3-4 (OR, 1.79; 95% CI, 1.01-3.17; P = .05), comorbidities of pulmonary disease (OR, 2.99; 95% CI, 1.67-5.34; P < .01) and diabetes mellitus (OR, 2.49; 95% CI, 1.58-3.94; P < .01), distal anastomosis level at below knee femoropopliteal BGP (OR, 2.01; 95% CI, 1.26-3.22; P < .01), femorotibial BGP (OR, 2.40; 95% CI, 1.37-4.19; P < .01), and popliteopedal BGP (OR, 92.39; 95% CI, 11.13-766.98; P < .01). One health care facility had significantly fewer AEs than the other two (OR, 0.21; 95% CI, 0.13-0.35; P < .01). Conclusion: Age, gender, comorbidity, and type of surgery are all independent predictors of AE occurrence in vascular surgery. After adjustment for differences in these factors, one health care facility still had lower AE occurrence, which needs to be examined further.@en