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Directed acyclic graphs to minimise bias and optimise causal inference in SNAP-3: an observational cohort study of frailty, multimorbidity, and delirium in older surgical patients
Claire Jane Swarbrick, Helen Abigail Blake, Peter Martin, Judith S.L. Partridge, Iain Keith Moppett. British Journal of Anaesthesia, 2025-05-26
Topic: Risk, prevention and care in population studies
DAGs provide visual representations of assumptions made, and provide an objective approach to appropriate statistical adjustments. Key nodes within all the DAGs included age, dementia, genetic predisposition, hearing and visual impairment, length of stay, malignancy, operative severity, polypharmacy, postoperative perioperative medicine service, preoperative clinic review, sex, social deprivation, urgency, with delirium, frailty, multimorbidity, interaction, morbidity acting as exposures, or outcomes in certain DAGs. DAGs provide a transparent framework for statistical decision-making in observational research. We provide an overview of DAGs using the SNAP-3 DAGs as examples to explain fundamental concepts for developing and using causal diagrams. This overview acknowledges the complexities of exploring clinical relationships and the assumptions that are necessary, providing an opportunity for critique of the relationships described and refinements for future studies.
Cite this study APA, Vancouver, BibTeX · download .bib or .ris
APA 7th
Swarbrick, C. J., Blake, H. A., Martin, P., Partridge, J. S., & Moppett, I. K. (2025). Directed acyclic graphs to minimise bias and optimise causal inference in SNAP-3: an observational cohort study of frailty, multimorbidity, and delirium in older surgical patients. British Journal of Anaesthesia. https://doi.org/10.1016/j.bja.2025.04.027
Vancouver
Swarbrick CJ, Blake HA, Martin P, Partridge JS, Moppett IK. Directed acyclic graphs to minimise bias and optimise causal inference in SNAP-3: an observational cohort study of frailty, multimorbidity, and delirium in older surgical patients. British Journal of Anaesthesia. 2025. doi:10.1016/j.bja.2025.04.027. PMID: 40425394.
BibTeX
@article{swarbrick2025-40425394,
author = {Swarbrick, Claire Jane and Blake, Helen Abigail and Martin, Peter and Partridge, Judith S.L. and Moppett, Iain Keith},
title = {{Directed acyclic graphs to minimise bias and optimise causal inference in SNAP-3: an observational cohort study of frailty, multimorbidity, and delirium in older surgical patients}},
journal = {British Journal of Anaesthesia},
year = {2025},
doi = {10.1016/j.bja.2025.04.027},
pmid = {40425394},
url = {https://doi.org/10.1016/j.bja.2025.04.027}
}
Built from the record alzhub holds for this paper, not looked up. Volume, issue and page numbers are not held in the record. Check the citation against the original before you use it.
Key findings
- DAGs provide visual representations of assumptions made, and provide an objective approach to appropriate statistical adjustments.
- Key nodes within all the DAGs included age, dementia, genetic predisposition, hearing and visual impairment, length of stay, malignancy, operative severity, polypharmacy, postoperative perioperative medicine service, preoperative clinic review, sex, social deprivation, urgency, with delirium, frailty, multimorbidity, interaction, morbidity acting as exposures, or outcomes in certain DAGs.
- DAGs provide a transparent framework for statistical decision-making in observational research.
- We provide an overview of DAGs using the SNAP-3 DAGs as examples to explain fundamental concepts for developing and using causal diagrams.
- This overview acknowledges the complexities of exploring clinical relationships and the assumptions that are necessary, providing an opportunity for critique of the relationships described and refinements for future studies.
Why it matters
This methodological paper describes how directed acyclic graphs were used in the SNAP-3 observational cohort study of frailty, multimorbidity, and delirium in older surgical patients. It provides a framework for statistical decision-making but reports no treatment, cure, or prevention for Alzheimer's disease.
Study details
- Study designcohort study
- Evidence strengthModerate
How this study scored 55/100
Published in a peer-reviewed journal, and it is a cohort study following people over time. Scored zero for sample size, effect reported, studied in people and randomised / blinded because the record does not state it.
| Component | Points | Why |
|---|---|---|
| Journal tier | 7 / 10 | Tier 3 — peer-reviewed journal (British Journal of Anaesthesia) |
| Journal's citation record | 3 / 4 | British Journal of Anaesthesia: journal h-index 288 (OpenAlex, 2026-10-29) |
| Study design | 7 / 12 | A cohort study following people over time |
| Strength of evidence | 3 / 5 | Rated “moderate” in our summary |
| Peer-review validation | 10 / 10 | Peer-reviewed. Published as an article in a named peer-reviewed journal. |
| How recent | 4 / 5 | 2025 — within 3 year(s) of the newest study here |
| Sample size | 0 / 4 | Participant count not stated — scores zero (not stated in the record — scored 0) |
| Effect reported | 0 / 3 | No effect size reported — scores zero (not stated in the record — scored 0) |
| Studied in people | 0 / 3 | Not stated whether this was studied in people — scores zero (not stated in the record — scored 0) |
| Randomised / blinded | 0 / 2 | No randomisation or blinding stated — scores zero (not stated in the record — scored 0) |
| Times cited | 3 / 7 | Cited 15 times (OpenAlex, 2026-10-10) |
| Citations per year | 2 / 5 | 5.0 citations a year over 3 year(s) since 2025 |
| Impact for its field and year | 4 / 6 | Cited 13.1× the average for papers of its field and year (OpenAlex FWCI) |
| Cited by studies here | 0 / 6 | No other study in this library cites it |
| Still being cited | 2 / 4 | Cited 15 times in 2024–2026 (2026 still in progress; OpenAlex) |
| Senior author's track record | 2 / 4 | Last-listed author Iain Keith Moppett: h-index 42 (OpenAlex, whole career) |
| Institution's track record | 2 / 3 | University College London: institution h-index 2,029 (OpenAlex) |
| Multi-centre collaboration | 2 / 3 | OpenAlex lists 7 institution(s) in 1 country |
| Indexed in PubMed | 2 / 2 | Indexed in PubMed (PMID 40425394) |
| Free to read | 2 / 2 | Free to read |
| Total | 55 / 100 | — |
What each of these 20 components measures, and what this score is not →
Read the original
- DOI: 10.1016/j.bja.2025.04.027
- PubMed: 40425394
- Original source →
- Free full text: British Journal of Anaesthesia →
Full text: free to read — OpenAlex lists this copy as free to read: the link above (checked 6 Feb 1020).
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