Associations of Postoperative Delirium With Perioperative Frailty Worsening and Their Combined Effect on 1-Year Mortality in Older Surgical Patients

Associations of Postoperative Delirium With Perioperative Frailty Worsening and Their Combined Effect on 1-Year Mortality in Older Surgical Patients: A Prospective Cohort Study

Postoperative delirium (POD) is a frequent complication in older surgical patients and is associated with adverse outcomes, while frailty is also highly prevalent during the perioperative period. This study aimed to determine whether POD accelerates perioperative frailty worsening and to assess the effect of their coexistence on 1-year mortality.

Study Overview

• Status: Completed
• Conditions: Mortality; Postoperative Delirium (POD); Recovery of Function; Frailty at Older Adults

• Study Type: Observational
• Enrollment (Actual): 6196

Contacts and Locations

Study Locations

• China
  • Beijing Municipality
    • Beijing, Beijing Municipality, China, 100853
      • 28 Fuxing Road, Haidian District

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Patients were divided into postoperative delirium (POD) and non-POD groups based on delirium occurrence within 7 days after surgery. Follow-up assessments were conducted at 30 days and 1 year postoperatively to evaluate frailty change and survival outcomes.

Description

Inclusion criteria:

1. Aged ≥65 years;
2. Scheduled for elective non-cardiac, non-neurosurgical procedures;
3. Consented to undergo preoperative health and functional state assessments.

Exclusion criteria:

1. Had severe dementia, language disorders, significant hearing or visual impairments, or were in a coma;
2. Had Mini-Mental State Examination (MMSE) scores below the established educational thresholds: <18 for illiterate individuals, <21 for those with primary education (≤6 years), and <25 for those with secondary education or higher (>6 years)
3. Underwent local anesthesia or monitored anesthesia care;
4. Had an operative time ≤30 minutes;
5. Incomplete preoperative FRAIL scale assessment;
6. Missing postoperative delirium data;
7. Incomplete FRAIL scale assessment at 1 month postoperatively.

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort
A retrospective cohort study based on prospectively collected data.; Patients were classified into POD and non-POD groups according to the occurrence of delirium within 7 days after surgery. The study examined the association between POD and worsened frailty at 1 month, and their combined effect on 1-year mortality.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
The primary outcome was worsened frailty at one month after surgery.	Frailty was assessed preoperatively by trained researchers using the FRAIL scale, which includes five items: fatigue, resistance, ambulation, illnesses, and weight loss. Each item scores 0 or 1, for a total of 0-5 points, with higher scores indicating greater frailty. Patients were categorized as robust (0), pre-frail (1-2), or frail (3-5). A follow-up frailty assessment was conducted one month postoperatively via telephone. Frailty change was defined as the difference between postoperative and preoperative scores: ≤0 indicated stable/improved frailty, and >0 indicated worsened frailty.	At one month after surgery.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
The secondary outcome was 1-year all-cause mortality.	A structured telephone follow-up was conducted one year after surgery to determine outcomes.	At one year after surgery.

Collaborators and Investigators

• Sponsor: Chinese PLA General Hospital

Study record dates

Study Major Dates

• Study Start (Actual): April 1, 2020
• Primary Completion (Actual): April 30, 2022
• Study Completion (Actual): April 30, 2023

Study Registration Dates

• First Submitted: November 21, 2025
• First Submitted That Met QC Criteria: November 21, 2025
• First Posted (Estimated): December 2, 2025

Study Record Updates

• Last Update Posted (Estimated): December 9, 2025
• Last Update Submitted That Met QC Criteria: December 7, 2025
• Last Verified: October 1, 2025

More Information

Terms related to this study

• Keywords: older adults; frailty; postoperative delirium; one year mortality; frailty worsening
• Additional Relevant MeSH Terms: Neurologic Manifestations; Nervous System Diseases; Mental Disorders; Postoperative Complications; Pathologic Processes; Confusion; Neurobehavioral Manifestations; Neurocognitive Disorders; Delirium; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Frailty; Emergence Delirium
• Other Study ID Numbers: PLAGH - FRAIL

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