ALB and chronic obstructive pulmonary disease: We found that age, gender, ASA classification ≥ 3, dependent function status, smoking, COPD, diabetes mellitus, coronary heart disease, arrhythmia, cerebrovascular disease, dementia, chronic renal failure, hip arthroplasty, delayed surgery, preoperative creatinine, preoperative serum albumin were the risk factors of POP via meta‐analysis of 10 included studies.