Sex-Dependent Risk of Postoperative Delirium and Mediating Effects of Family Visits

NCT07502391 | Recruiting

• 1 other identifier: 2025-02296
• Study Type: observational
• Target: 471
• Locations: 1 country
• Sites: 1

Brief Summary

Postoperative delirium is a common and serious complication after surgery, affecting 10-40% of older patients undergoing non-cardiac procedures. It is characterized by sudden changes in attention, awareness, and thinking that fluctuate throughout the day. Delirium is associated with longer hospital stays, higher mortality, worse long-term brain function, and substantially increased healthcare costs. While several risk factors are known, it remains unclear whether a patient's sex independently influences the risk of developing postoperative delirium, as existing studies have produced conflicting results and were often not designed to specifically examine sex differences.Family visitation is a promising non-drug approach to preventing delirium. Studies in intensive care patients have shown that those who receive family visits have a significantly lower risk of developing delirium. However, it is unknown whether men and women receive different amounts of family visits after surgery, and whether any such difference could help explain sex-based disparities in delirium risk. Given that traditional gender roles in caregiving persist, women - who often serve as primary caregivers in their families - may receive fewer visits when they themselves become patients.This prospective observational study led by the University of Zurich will enroll 471 patients aged 65 years or older undergoing non-cardiac surgery lasting at least 2 hours under general or spinal anesthesia. The primary aim is to determine whether female patients have a higher risk of developing postoperative delirium within three days after surgery compared to male patients. Delirium will be assessed twice daily using the 4 A's Test (4AT), a validated and standardized screening tool. The secondary aim is to evaluate whether female patients receive fewer family visits than male patients and whether any difference in visitation mediates the sex-dependent delirium risk. Family visits will be recorded using an anonymous sign-in sheet placed in the patient's room. The study does not involve any experimental interventions; all patients receive standard clinical care. Participation is voluntary, and withdrawal is possible at any time without affecting medical treatment.

Conditions

Postoperative Delirium (POD); Sex Differences

Outcome Measures

Primary Outcomes (1)

• Postoperative Delirium

  The primary outcome is presence of delirium as assessed by the 4AT test. A 4AT score of 4 or above will be used for dichotomous assessment of the primary outcome presence of delirium. Participants will be assessed daily in the morning and the evening.

  Starting on postoperative day (POD) 1 and continuing until POD 3, or discharge - whichever comes first.

Secondary Outcomes (1)

• Family Visits

  Starting on postoperative day (POD) 1 and continuing until POD 3, or discharge - whichever comes first

Study Arms (2)

Female

Female patients aged 65 years or above with scheduled non-cardiac surgery with expected surgery duration ≥ 2 hours under either general or spinal anesthesia.

Male

Male patients aged 65 years or above with scheduled non-cardiac surgery with expected surgery duration ≥ 2 hours under either general or spinal anesthesia.

Eligibility Criteria

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

Study Population

Patients aged 65 and older who are having noncardiac surgery

You may qualify if:

• Informed consent as documented by signature;
• ≥65 years of age;
• Scheduled non-cardiac surgery with expected surgery duration ≥ 2 hours;
• Under either general or spinal anesthesia.

You may not qualify if:

• Known drug or alcohol abuse;
• Requirement for postoperative ventilation;
• Current participation in another study with an investigational drug;
• Inability to complete the study assessments.

Sponsors & Collaborators

• Julian Rössler: lead

Study Sites (1)

Universitätsspital Zürich

Zurich, Switzerland

RECRUITING

MeSH Terms

Conditions

Emergence Delirium

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: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: SPONSOR INVESTIGATOR
• PI Title: Attending Physician, Institute of Anesthesiology and Perioperative Medicine

Study Record Dates

• First Submitted: March 25, 2026
• First Posted: March 31, 2026
• Study Start: May 5, 2026
• Primary Completion (Estimated): December 31, 2028
• Study Completion (Estimated): December 31, 2028
• Last Updated: June 1, 2026

Record last verified: 2026-03

Locations

CH (1)