Validation of a Risk Assessment Model for Postoperative Delirium Based on Artificial Intelligence

Postoperative delirium (POD) is a frequent postoperative complication in the elderly, characterised by fluctuating disturbances in attention, awareness, and cognition. Identifying the patients at highest risk of developing POD was the aim of the artificial intelligence (AI)-based algorithm PIPRA. This prospective cohort study is to externally validate the AI-based PIPRA algorithm. The primary endpoint is the performance (AUC) of the PIPRA algorithm in predicting POD. The secondary endpoint is the performance (AUC) of the clinicians in predicting POD (and how it compares with the performance of the PIPRA algorithm).

Study Overview

• Status: Recruiting
• Conditions: Postoperative Delirium (POD)
• Intervention / Treatment: Other: Data collection on POD for calculation of the PIPRA score

Detailed Description

Perioperative neurocognitive disorders (PND) include postoperative delirium (POD) and postoperative neurocognitive disorder or postoperative cognitive dysfunction (POCD). POD is recognised as a frequent postoperative complication in the elderly, occurring in 10% to 50% of older patients after major surgical procedures. POD usually occurs in the early postoperative period and is defined as an acute neuropsychiatric disorder. It is characterised by fluctuating disturbances in attention, awareness, and cognition. The American Society of Enhanced Recovery and Perioperative Quality Initiative Joint Consensus Statement on Postoperative Delirium Prevention recommend focusing on identifying those patients at highest risk of developing POD. Identifying these highest risk patients was the aim of the artificial intelligence (AI)-based algorithm PIPRA, which was created based on an individual participant data (IPD) meta-analysis including more than 2500 patients. This risk-prediction algorithm uses standard data (i.e. age, height, weight, history of delirium, cognitive impairment, ASA status, number of medications, preoperative C reactive protein (CRP), surgical risk and laparotomy), which are routinely collected before surgery. PIPRA was internally validated with an area under the curve (AUC) of 0.837 with 95% confidence interval 0.808 to 0.865, when plotting the true positive rate against the false positive rate. The aim of this prospective cohort study is to externally validate the AI-based PIPRA algorithm.

First, the anaesthesiologist in charge will be asked to evaluate, based on his/her experience (quantified in years of anaesthesia practice), the risk for the included patient to develop POD (categorised as low, intermediate, high or very high). Next, an investigator will assess included patents in a systematic and reproductible manner. After surgery, an investigator will visit the patient twice daily from postoperative day 1 to 5 or until hospital discharge (whichever occurs first) to screen for delirium using the 4AT or the ICDSC. The PIPRA score will be calculated separately by the coordinating study centre.

• Study Type: Observational
• Enrollment (Estimated): 950

Contacts and Locations

• Study Contact: Name: Luzius Steiner, Prof. Dr. med.; Phone Number: +41 61 265 73 20; Email: luzius.steiner@usb.ch

Study Locations

• Switzerland
  • Basel, Switzerland, 4031
    • Recruiting
    • University Hospital Basel, Anaesthesiology
    • Contact: Luzius Steiner, Prof. Dr. med.; Email: luzius.steiner@usb.ch
    • Principal Investigator: Luzius Steiner, Prof. Dr. med.
  • Genève, Switzerland, 1205
    • Recruiting
    • Hôpitaux Universitaires de Genève, Anesthesiology
    • Contact: Bernhard Walder, Prof. Dr. med.; Email: bernhard.walder@hcuge.ch
    • Principal Investigator: Bernhard Walder, Prof. Dr. med.
  • Lausanne, Switzerland, 1011
    • Recruiting
    • Centre Hospitalier Universitaire Vaudois, Anesthesiology
    • Contact: John Gaudet, Dr. med.; Email: john.gaudet@chuv.ch
    • Principal Investigator: John Gaudet, Dr. med.

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 60 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

• Sampling Method: Probability Sample

Study Population

Consecutive surgical patients at multiple sites in Switzerland.

Description

Inclusion Criteria:

• Surgical patients ≥60 years old
• Planned postoperative hospital stay ≥ 2 days
• Consent from patient

Exclusion Criteria:

• Preoperative delirium
• Insufficient knowledge in German or French
• Intracranial surgery
• Cardiac surgery
• Surgery within the two previous weeks
• Patient unable to consent

Study Plan

How is the study designed?

Design Details

• Observational Models: Cohort
• Time Perspectives: Prospective

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in 4 'A's Test (4AT) to evaluate presence of POD	4 'A's Test (4AT) is a bedside medical scale with 4 parameters: Alertness; Abbreviated mental test-4 (AMT4); Attention (months backwards test); Acute change or fluctuating course. The score range is 0-12, with scores of 4 or more suggesting possible delirium. Scores of 1-3 suggest possible cognitive impairment.	Twice daily (morning and evening) from postoperative day 1 until postoperative day 5, hospital discharge or a positive diagnosis of POD, whichever occurs first.
Change in Intensive Care Delirium Screening Checklist (ICDSC) to evaluate presence of POD	The ICDSC is an 8-item delirium screening instrument (range: 0-8 points) that evaluates a patient's level of consciousness, inattention, disorientation, hallucinations or delusions, psychomotor activity, inappropriate speech or mood, sleep disturbance and fluctuation of symptoms (no delirium with a score of 0, less than clinical threshold symptoms of delirium with a score of 1-3 and clinical delirium with a score of 4-8).	Twice daily (morning and evening) from postoperative day 1 until postoperative day 5, hospital discharge or a positive diagnosis of POD, whichever occurs first.

Collaborators and Investigators

• Sponsor: University Hospital, Basel, Switzerland
• Collaborators: Innosuisse - Swiss Innovation Agency
• Investigators: Principal Investigator: Luzius Steiner, Prof. Dr. med., University Hospital Basel, Department of Anaesthesiology

Study record dates

Study Major Dates

• Study Start (Actual): November 21, 2022
• Primary Completion (Estimated): July 1, 2024
• Study Completion (Estimated): September 1, 2024

Study Registration Dates

• First Submitted: November 23, 2022
• First Submitted That Met QC Criteria: November 28, 2022
• First Posted (Actual): December 6, 2022

Study Record Updates

• Last Update Posted (Actual): February 20, 2024
• Last Update Submitted That Met QC Criteria: February 19, 2024
• Last Verified: February 1, 2024

More Information

Terms related to this study

• Keywords: Perioperative neurocognitive disorders (PND); Postoperative cognitive dysfunction (POCD); Acute neuropsychiatric disorder; Cognitive testing; Artificial intelligence (AI)-based algorithm PIPRA; Intensive Care Delirium Screening Checklist (ICDSC); 4 "A" Tests (4AT)
• Additional Relevant MeSH Terms: Mental Disorders; Pathologic Processes; Nervous System Diseases; Postoperative Complications; Neurologic Manifestations; Confusion; Neurobehavioral Manifestations; Neurocognitive Disorders; Delirium; Emergence Delirium
• Other Study ID Numbers: 2022-00990; am21Dell- Kuster

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No