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

NCT07322744 | Completed

• 1 other identifier: LMR - POD
• Study Type: observational
• Target: 6,475
• Locations: 1 country
• Sites: 1

Brief Summary

Both frailty and a reduced preoperative lymphocyte-to-monocyte ratio (LMR) are known risk factors for postoperative delirium (POD). However, whether the relationship between LMR and POD varies by frailty status remains unclear. This study aimed to evaluate the frailty-stratified association between preoperative LMR and POD in older surgical patients.

Conditions

Postoperative Delirium (POD); Frailty at Older Adults; Lymphocyte

Keywords

postoperative delirium; frailty; older surgical patients; lymphocyte-to-monocyte ratio

Outcome Measures

Primary Outcomes (1)

• The primary outcome was the occurrence of postoperative delirium (POD).

  The primary outcome was the occurrence of POD, evaluated by trained researchers using the 3-Minute Diagnostic Interview for Confusion Assessment Method (3D-CAM).

  POD assessment was performed twice daily for up to seven consecutive postoperative days or until hospital discharge, whichever occurred first.

Study Arms (1)

A retrospective cohort study based on prospectively collected data.

Patients were grouped according to the preoperative lymphocyte-to-monocyte ratio (LMR), calculated as the lymphocyte count divided by the monocyte count. Lymphocyte and monocyte values were obtained from the most recent preoperative laboratory test. Frailty was assessed one day before surgery using the FRAIL scale, which comprises five domains: fatigue, resistance, ambulation, illnesses, and weight loss. Each item is scored as 0 or 1, yielding a total score ranging from 0 to 5, with higher scores indicating greater frailty. Based on the total score, patients were categorized as robust (0 points), pre-frail (1-2 points), or frail (3-5 points).

Eligibility Criteria

• Age: 65 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

Patients were grouped according to the preoperative lymphocyte-to-monocyte ratio (LMR) and were further stratified into subgroups based on frailty status, which was assessed one day before surgery using the FRAIL scale. Postoperative delirium was assessed using the 3-Minute Diagnostic Interview for Confusion Assessment Method (3D-CAM) for seven consecutive postoperative days or until hospital discharge, whichever occurred first.

You may qualify if:

• Aged ≥65 years;
• Underwent elective noncardiac, nonneurosurgical procedures;
• Completed the preoperative health and functional status questionnaire.

You may not qualify if:

• 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.

Sponsors & Collaborators

• Chinese PLA General Hospital: lead

Study Sites (1)

28 Fuxing Road, Haidian District

Beijing, China

Location

MeSH Terms

Conditions

Emergence Delirium; Frailty

Condition Hierarchy (Ancestors)

Delirium; Confusion; Neurobehavioral Manifestations; Neurologic Manifestations; Nervous System Diseases; Postoperative Complications; Pathologic Processes; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Neurocognitive Disorders; Mental Disorders

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: RETROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Deputy Chief of administration, Anesthesiology

Study Record Dates

• First Submitted: December 23, 2025
• First Posted: January 7, 2026
• Study Start: April 1, 2020
• Primary Completion: April 30, 2022
• Study Completion: December 30, 2023
• Last Updated: January 9, 2026

Record last verified: 2025-11

Data Sharing

• IPD Sharing: Will not share

Locations

CN (1)