Risk Factors for Postoperative Neurocognitive Disorders in Older Patients Undergoing Non-Cardiac, Non-Neurosurgical Procedures: A PRISMA-ScR Scoping Review v1
Bibliographic record
Abstract
Background:Postoperative neurocognitive disorders (PNDs), including delirium and longer-term cognitive dysfunction, are common in older adults undergoing surgery and are associated with significant morbidity. Numerous risk factors have been described in the literature, but there is a lack of synthesis regarding their nature, categorisation, and study methods. A comprehensive mapping is needed to inform clinical practice and future research. Objective:This protocol outlines the methodology for a scoping review aiming to map the extent, nature, and characteristics of published literature on risk factors for PNDs in patients aged 65 years and older undergoing surgery. Secondary objectives include categorising risk factors by perioperative timing, describing study populations and surgical contexts, identifying the definitions and diagnostic tools used, and highlighting research gaps. Methods:This scoping review will follow the PRISMA-ScR guidelines. A comprehensive literature search will be conducted in tthe MEDLINE database for studies published since 1 January 2000, without language restriction. Eligible sources will include prospective and retrospective observational studies, randomised controlled trials, and systematic or narrative reviews, examining patients aged ≥65 years who have undergone non-cardiac, non-neurosurgical, and non-carotid surgery. Two reviewers will independently screen titles, abstracts, and full texts for inclusion. Data extraction will capture patient and study characteristics, surgical context, types and definitions of PNDs, risk factors evaluated, and main findings. Quality appraisal will be performed for informational purposes using the Newcastle-Ottawa Scale and other appropriate risk of bias tools, depending on study design. Results will be presented through numerical, tabular, and narrative synthesis. Expected Outcomes:This review will provide a comprehensive mapping of reported risk factors for PNDs in older adults, identify heterogeneity in definitions, measurement tools, and study contexts, and reveal key gaps in current research. Findings will inform clinicians and guide future investigations in this important area. Registration:This protocol will be registered and made publicly available via Protocols.io.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.087 | 0.201 |
| Meta-epidemiology (narrow) | 0.002 | 0.003 |
| Meta-epidemiology (broad) | 0.010 | 0.013 |
| Bibliometrics | 0.025 | 0.028 |
| Science and technology studies | 0.003 | 0.003 |
| Scholarly communication | 0.006 | 0.006 |
| Open science | 0.006 | 0.007 |
| Research integrity | 0.004 | 0.003 |
| Insufficient payload (model declined to judge) | 0.009 | 0.001 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".