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Dementia and postoperative outcomes in older adults: national estimates and mechanistic pathways from a US cohort study
Dany Y. Matar, John J. Lee, Tobias Niederegger, Jia Wei Tee, Thomas Schaschinger, Dennis Paul Orgill, Gabriel Hundeshagen, Adriana Christine Panayi. Age and Ageing, 2026-05-01
Topic: Risk, prevention and care in population studies
Among 547 310 older adults undergoing surgery, 43 041 (7·9%) had preoperative dementia. After adjustment, dementia was associated with higher 30-day mortality (aRR 1·64, 95% CI 1·50-1·80), increased postoperative delirium (aRR 3·09) and greater LOI (aRR 1·24), but not with surgical complications (aRR 1·02). Delirium mediated 46·0% (95% CI 38·6-55·9) of the dementia-associated mortality risk, while LOI mediated 26·0% (22·7-30·2). LOI accounted for most of the effect on prolonged hospitalisation (42·6%) and new institutionalisation (70·2%), whereas delirium explained only a small proportion of LOI (14·2%). Dementia-associated mortality was most pronounced among patients with lower frailty and in elective surgical settings. Dementia influences postoperative outcomes through distinct, pathway-specific mechanisms. Mortality is driven primarily by postoperative delirium, whereas healthcare utilisation is largely mediated by loss of functional independence.
Cite this study APA, Vancouver, BibTeX · download .bib or .ris
APA 7th
Matar, D. Y., Lee, J. J., Niederegger, T., Tee, J. W., Schaschinger, T., Orgill, D. P., et al. (2026). Dementia and postoperative outcomes in older adults: national estimates and mechanistic pathways from a US cohort study. Age and Ageing. https://doi.org/10.1093/ageing/afag155
Vancouver
Matar DY, Lee JJ, Niederegger T, Tee JW, Schaschinger T, Orgill DP, et al. Dementia and postoperative outcomes in older adults: national estimates and mechanistic pathways from a US cohort study. Age and Ageing. 2026. doi:10.1093/ageing/afag155. PMID: 42200480.
BibTeX
@article{matar2026-42200480,
author = {Matar, Dany Y. and Lee, John J. and Niederegger, Tobias and Tee, Jia Wei and Schaschinger, Thomas and Orgill, Dennis Paul and Hundeshagen, Gabriel and Panayi, Adriana Christine},
title = {{Dementia and postoperative outcomes in older adults: national estimates and mechanistic pathways from a US cohort study}},
journal = {Age and Ageing},
year = {2026},
doi = {10.1093/ageing/afag155},
pmid = {42200480},
url = {https://doi.org/10.1093/ageing/afag155}
}
Built from the record alzhub holds for this paper, not looked up. Volume, issue and page numbers are not held in the record. The record names 8 authors; APA and Vancouver show the first six, BibTeX and the downloads carry all of them. Check the citation against the original before you use it.
Key findings
- Among 547 310 older adults undergoing surgery, 43 041 (7·9%) had preoperative dementia.
- After adjustment, dementia was associated with higher 30-day mortality (aRR 1·64, 95% CI 1·50-1·80), increased postoperative delirium (aRR 3·09) and greater LOI (aRR 1·24), but not with surgical complications (aRR 1·02).
- Delirium mediated 46·0% (95% CI 38·6-55·9) of the dementia-associated mortality risk, while LOI mediated 26·0% (22·7-30·2).
- LOI accounted for most of the effect on prolonged hospitalisation (42·6%) and new institutionalisation (70·2%), whereas delirium explained only a small proportion of LOI (14·2%).
- Dementia-associated mortality was most pronounced among patients with lower frailty and in elective surgical settings.
Why it matters
In this large US cohort, preoperative dementia was associated with higher 30-day mortality and postoperative delirium after surgery, with delirium mediating much of the mortality risk and loss of independence mediating healthcare use. The findings highlight pathways for monitoring and prevention of complications, not a treatment or cure for dementia itself.
Study details
- Study designcohort study
- Evidence strengthModerate
How this study scored 50/100
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 randomized / blinded because the record does not state it.
| Component | Points | Why |
|---|---|---|
| Journal tier | 7 / 10 | Tier 3 — peer-reviewed journal (Age and Ageing) |
| Journal's citation record | 2 / 4 | Age and Ageing: journal h-index 231 (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 | 5 / 5 | 2026 — within 1 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) |
| Randomized / blinded | 0 / 2 | No randomization or blinding stated — scores zero (not stated in the record — scored 0) |
| Times cited | 1 / 7 | Cited 2 times (OpenAlex, 2026-10-10) |
| Citations per year | 1 / 5 | 1.0 citations a year over 2 year(s) since 2026 |
| Impact for its field and year | 4 / 6 | Cited 11.3× 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 | 0 / 4 | Cited 2 times in 2024–2026 (2026 still in progress; OpenAlex) |
| Senior author's track record | 2 / 4 | Last-listed author Adriana Christine Panayi: h-index 43 (OpenAlex, whole career) |
| Institution's track record | 3 / 3 | Harvard University: institution h-index 3,235 (OpenAlex) |
| Multicenter collaboration | 3 / 3 | OpenAlex lists 12 institution(s) in 4 countries |
| Indexed in PubMed | 2 / 2 | Indexed in PubMed (PMID 42200480) |
| Free to read | 0 / 2 | Behind a paywall — scores zero |
| Total | 50 / 100 | — |
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