ALB and chronic obstructive pulmonary disease: The logistic regression analysis showed that the risk factors significantly associated with the occurrence of SSI were male gender, elderly, heavy smoking, COPD, ASA III–IV, uncontrolled diabetes mellitus, BMI > 27.9, lower level of albumin, hypemricemia, the longer operation time, more blood loss, and the higher NHSN risk index score (1 0r 2).