Preoperative Lymphocyte-to-Monocyte Ratio and Postoperative Delirium by Frailty Status in Older Surgical Patients

Exclusion Criteria

• •Severe dementia, language disorders, significant hearing or visual impairments, or coma;
• •Cognitive function below the Mini-Mental State Examination thresholds (\<18 for illiterate individuals, \<21 for individuals with primary education, and \<25 for individuals with secondary education or higher);
• •Surgery performed under local anesthesia or monitored anesthesia care;
• •Missing lymphocyte or monocyte count data;
• •Missing postoperative delirium assessment;
• •Incomplete preoperative FRAIL scale evaluation;
• •Missing data for more than 20% of covariates.