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Cognitive and Behavioral ImpairmentNCT07135336

Incidence of Postoperative Cognitive Decline in Patients With Preexisting Cognitive Impairment

An observational study of Cognitive and Behavioral Impairment, run by Peking University Shenzhen Hospital at 1 site in China.

Recruiting

Looking for participants now. Contact the study team or a site below to ask about taking part.

Sites and contacts
Official record
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Trial summary

This study aims to find out how often memory and thinking problems happen after surgery in people who already have memory issues before their operation. These memory problems are called postoperative cognitive decline (POCD). Read more about this study

Who is it for?
Ages 60 years and olderHealthy volunteers can take part
Conditions the study is for
Cognitive and Behavioral Impairment
What is being tested?
surgery and norma
Type of treatment
Surgery or procedure
How many people
340 participants
Where
1 siteChina
Study dates
15 Jul 2025to 1 Jul 2027
How long will I take part?
1 Year
Phase
Observational
Are there results?
Not yet: the study is under way

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 60 years and older
  • All sexes
  • Healthy volunteers accepted
  • Adult, Older adult

Study population: Patients aged 60 years and older with preexisting cognitive impairment undergoing elective non-cardiac surgery under general anesthesia at Peking University Shenzhen Hospital will be recruited between June 2025 and December 2027. A normative reference group of cognitively normal elderly individuals, matched by age and sex, will also be enrolled from the same hospital during the same period. All participants must reside in Shenzhen and be able to communicate in Mandarin.

Who may be able to join

  • Age ≥ 60 years
  • Preoperative screening with MMSE and MoCA-B indicating mild cognitive impairment (MCI) or mild dementia
  • Undergoing elective non-cardiac surgery under general anesthesia
  • Age ≥ 60 years
  • No history of general anesthesia surgery within the past 12 months
  • Mini-Cog score > 1

Who cannot join

  • Expected difficulty in completing neuropsychological assessments (e.g., inability to communicate in Mandarin, blindness, or deafness)
  • Usual residence outside Shenzhen
  • Normative Reference Group
  • Planned elective surgery under general anesthesia within the next 12 months
  • History of suspected or diagnosed cognitive impairment, or screening indicating cognitive impairment using MMSE and MoCA-B
  • Expected difficulty in completing neuropsychological assessments (e.g., inability to communicate in Mandarin, blindness, or deafness)
  • Usual residence outside Shenzhen

Trial locations and contacts

1 site in 1 country. Contact the study team or a site near you to ask about taking part.

China1 site, 1 recruiting
  • Peking University Shenzhen Hospital

    Shenzhen, Guangdong

    Yaqian Yu, +86 13528403653, meayaqian@gmail.com

    Recruiting

Other trials in China

About this study

Official title: Incidence of Postoperative Cognitive Decline in Surgical Patients With Preexisting Cognitive Impairment: A Prospective Cohort Study

This study aims to find out how often memory and thinking problems happen after surgery in people who already have memory issues before their operation. These memory problems are called postoperative cognitive decline (POCD). Older adults with memory problems before surgery may be more likely to have trouble with thinking, memory, and daily activities after their operation. This study will follow patients who already have memory problems before surgery and see how their thinking and memory change after surgery. The results will help doctors better understand how to care for these patients before, during, and after surgery.

Read the detailed description

This is a single-center, prospective, single-arm cohort study designed to estimate the incidence of postoperative cognitive decline (POCD) in patients aged 60 years and older with preexisting cognitive impairment undergoing elective non-cardiac surgery under general anesthesia.

To calculate the incidence of POCD, a normative population of cognitively normal individuals will be recruited to provide reference data for the expected range of cognitive change over time in the absence of surgery. This normative sample is not a control group for intervention comparison but is used to establish population-based norms for cognitive test score changes.

Study Procedures:

Preoperative assessment (1 day before surgery):

Patients will be screened using the Mini-Cog test. Those with scores ≤1 will be further evaluated with the Mini-Mental State Examination (MMSE) and Beijing version of the Montreal Cognitive Assessment (MoCA-B).(This threshold is based on the Chinese expert consensus scoring criteria, which differ slightly from the international standard. According to the Chinese algorithm, a score of ≤1 encompasses cases where the clock drawing is incorrect and one to two words are recalled, or when no words are recalled at all, aligning functionally with a score of ≤2 in the international system. Therefore, our inclusion criterion of ≤1 under the Chinese system is equivalent in diagnostic implication to the widely accepted international cutoff of ≤2, which indicates high likelihood of cognitive impairment.) Eligible participants will be enrolled after informed consent is obtained. Neuropsychiatric symptoms will be assessed using the Neuropsychiatric Inventory-Questionnaire (NPI-Q). Dementia severity and functional ability will be evaluated using the Clinical Dementia Rating (CDR), Basic Activities of Daily Living (BADL), and Instrumental Activities of Daily Living (IADL) scales.

Intraoperative data collection:

Information regarding surgery and anesthesia will be obtained from the electronic medical records.

Postoperative follow-up (at 3 and 12 months):

All participants will undergo cognitive assessments using the MMSE and MoCA-B. Neuropsychiatric symptoms, dementia severity (if applicable), and functional abilities will also be reassessed. Follow-up will be scheduled to minimize participant burden, and home-based assessments will be arranged when necessary. Remote assessments will be documented if used.

Normative Population:

Cognitively normal individuals will be recruited from inpatients and outpatients of Peking University Shenzhen Hospital. They will undergo cognitive assessments at baseline, 3 months, and 12 months to provide normative data for the calculation of standardized cognitive changes.

Primary Outcome:

The primary outcome is the incidence of POCD at 3 months after surgery. Following the nomenclature recommendations by Evered et al., POCD is defined as objectively measurable cognitive decline occurring between 3 months and 7.5 years after surgery. The diagnosis of POCD in this study will be based on the Reliable Change Index (RCI), a standardized statistical method that accounts for normal variability and practice effects over time.

RCI is calculated as:

RCI = (ΔX_patient - Δμ_normative) / σ_normative

Where ΔX_patient is the individual's change score, Δμ_normative is the mean change in the normative group, and σ_normative is the standard deviation of change scores in the normative group.

A patient will be considered to have POCD if either:

At least two cognitive domains show an RCI ≤ -1.96, or

The combined Z-score of all cognitive tests is ≤ -1.96.

Follow-up Management and Missing Data Handling:

Participants will be followed at 3 and 12 months. If a participant is unable to attend, alternative arrangements will be made. Loss to follow-up will be documented with reasons, and missing data will be addressed using sensitivity analyses.

Being tested
surgery, norma
Keywords
postoperative cognitive decline, preexisting cognitive impairment
Medical subject headings
Postoperative Cognitive Complications

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • surgeryProcedure or surgery

    Patients with preexisting cognitive impairment undergoing elective non-cardiac surgery under general anesthesia.

  • normaOther

    Cognitively normal individuals who do not undergo surgery but complete the same cognitive assessments at baseline, 3 months, and 12 months for normative reference.

Study groups in NCT07135336
Study groupRoleWhat they receive
Preexisting Cognitive Impairment (PreCI) GroupPatients aged 60 years and older with preexisting cognitive impairment undergoing elective non-cardiac surgery under general anesthesia. These patients will receive standard perioperative care without any additional intervention. Cognitive function and neuropsychiatric status will be assessed before surgery, and at 3 and 12 months after surgery to determine the incidence of postoperative cognitive decline (POCD).
Receives: Procedure: surgery
Normative PopulationCognitively normal individuals recruited from inpatients and outpatients of Peking University Shenzhen Hospital. These participants will not undergo surgery but will complete the same cognitive assessments at baseline, 3 months, and 12 months. The normative data will be used to calculate the Reliable Change Index (RCI) for identifying clinically significant cognitive decline in the PreCI group.
Receives: Other: norma

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Incidence of Postoperative Cognitive Decline (POCD) at 3 Months

    The primary outcome is the incidence of objectively measurable postoperative cognitive decline (POCD) at 3 months in patients with preexisting cognitive impairment undergoing elective non-cardiac surgery under general anesthesia. The diagnosis of POCD will follow the nomenclature recommendations by Evered et al., which define POCD as cognitive decline occurring between 3 months and 7.5 years after surgery, determined by standardized score changes compared with a normative reference population.

    In this study, POCD will be identified using the Reliable Change Index (RCI), calculated as:

    RCI = (ΔX_patient - Δμ_normative) / σ_normative

    A patient will be diagnosed with POCD if:

    At least two cognitive domains show an RCI ≤ -1.96, or

    The combined Z-score of all cognitive tests is ≤ -1.96.

    Measured: 3 months after surgery

Secondary outcomes (5)
  1. Incidence of POCD at 12 Months

    Incidence of objectively measurable POCD at 12 months postoperatively, assessed using the same criteria as the primary outcome (RCI method).

    Measured: 12 months after surgery

  2. Neuropsychiatric Symptoms Assessed by NPI-Q

    Neuropsychiatric symptoms will be evaluated using the Neuropsychiatric Inventory-Questionnaire (NPI-Q), based on caregiver or informant reports. It assesses the presence, severity, and caregiver distress associated with 12 neuropsychiatric symptoms commonly seen in patients with cognitive impairment. For each symptom, severity is rated on a scale from 1 to 3 (1 = mild, 2 = moderate, 3 = severe), with a total severity score ranging from 0 to 36. Higher scores indicate more severe neuropsychiatric symptoms.

    Measured: 3 and 12 months after surgery

  3. Functional Ability Assessed by The Barthel Index

    The Barthel Index (BI) in an informant report was used for measuring basic ADL actual performance in this study. The BI is a questionnaire that consists of ten items: feeding, bathing, grooming, dressing, bowels, bladder, toilet use, transfer, mobility, and stairs. The summary score ranges from 0 to 100, with lower scores indicating a poorer basic ADL performance

    Measured: 3 and 12 months after surgery

  4. Dementia Severity Assessed by CDR

    The Clinical Dementia Rating (CDR) will be used to assess the severity of dementia by evaluating six cognitive and functional domains. Scores range from 0 (no impairment) to 3 (severe dementia). CDR scores will be recorded at each follow-up.

    Measured: 3 and 12 months after surgery

  5. Instrumental activities of daily living by The Lawton IADL

    Instrumental activities of daily living (IADL) will be assessed using the Lawton-Brody Instrumental Activities of Daily Living Scale, a widely validated and reliable tool for evaluating functional independence in older adults. The scale includes eight domains: using the telephone, shopping, preparing meals, housekeeping, laundry, using transportation, managing medications, and handling finances. The assessment will be conducted through informant-based interviews or direct patient self-report, depending on cognitive status. Each item is scored dichotomously (0 or 1): 1 point indicates independence in performing the activity 0 points indicates dependence or inability to perform the activity. The total score ranges from 0 to 8, with higher scores indicating greater functional independence. A total score ≤6 may suggest moderate to severe functional impairment.

    Measured: 3 and 12 months after surgery

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted22 Aug 2025
  2. Study start15 Jul 2025
  3. Primary completion1 Jan 2027 (estimated)
  4. Study completion1 Jul 2027 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Observational
Observational model
Cohort
Time perspective
Prospective
Enrolment
340 participants (estimated)
Target duration
1 Year
IDs, dates and publications
ClinicalTrials.gov ID
NCT07135336
Sponsor's protocol ID
2025(134)
Status last verified
Jul 2025
First submitted
25 Jun 2025
Last updated
22 Aug 2025
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
Undecided: De-identified data may be considered for sharing upon reasonable request after the study results have been published, subject to additional ethical approval.

Questions about this trial

What is this clinical trial studying?

An observational study of Cognitive and Behavioral Impairment, run by Peking University Shenzhen Hospital at 1 site in China.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 6 inclusion and 7 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: looking for participants now, as of the sponsor's last update on 22 Aug 2025. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in China. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

Contact Yaqian Yu (+86 13528403653, meayaqian@gmail.com), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Incidence of Postoperative Cognitive Decline (POCD) at 3 Months (time frame: 3 months after surgery). It is what the study was designed to measure, not a finding.

Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 22 Aug 2025.

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