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

January 8, 2026 updated by: Yanhong Liu, Chinese PLA General Hospital

Association Between Preoperative Lymphocyte-to-Monocyte Ratio and Postoperative Delirium According to Frailty Status in Older Surgical Patients: A Prospective Cohort Study

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.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Observational

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
6475

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • China
      • Beijing, China
        • 28 Fuxing Road, Haidian District

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Older Adult

Accepts Healthy Volunteers

No

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.

Description

Inclusion Criteria:

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

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.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort

Group / Cohort

A group or subgroup of participants in an observational study that is assessed for biomedical or health outcomes.
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).

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
The primary outcome was the occurrence of postoperative delirium (POD).
Time Frame: POD assessment was performed twice daily for up to seven consecutive postoperative days or until hospital discharge, whichever occurred first.
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.

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Chinese PLA General Hospital

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
April 1, 2020

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
April 30, 2022

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
December 30, 2023

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
December 23, 2025

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
December 23, 2025

First Posted (Estimated)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
January 7, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
January 9, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
January 8, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
November 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • LMR - POD

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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