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Delirium: more than a marker of baseline vulnerability
Rose Penfold, Alasdair M. J. MacLullich. Age and Ageing, 2026-05-01
Topic: Risk, prevention and care in population studies
Across several cohorts, delirium is emerging as an important prognostic signal, independent of chronic markers of baseline morbidity, that identifies patients at markedly increased risk of death or future dementia. Delirium was associated with substantially higher 90-day mortality overall [adjusted hazard ratio (HR) 3.45], but the strongest relative association was actually in those without baseline dementia (HR 4.40). In the DELPHIC population-based cohort, Tsui et al. showed that higher baseline cognition was associated with lower delirium risk , but if delirium occurred, it was often more severe and associated with greater future cognitive decline [4]. In a large acute general medicine cohort with long-term follow-up, Gan et al. reported that delirium was associated with prolonged admission, greater discharge care needs and increased mortality, with relatively more adverse outcomes in younger older adults (aged 65–74 years) without comorbid dementia [5]. In a population-based cohort of 23 558 older adults without pre-existing dementia, we observed a similar pattern: delirium was associated with higher 30-day mortality risk across the spectrum of long-term conditions [6]. Furthermore, we found that delirium was consistently associated with higher incident dementia risk, and the strongest relative association was in those with no or few long-term conditions. Taken together, the emerging signal across these studies is coherent: delirium appears to be the strongest prognostic marker of subsequent adverse outcomes in people with fewer pre-existing vulnerabilities. These findings have several important implications for clinical practice. The 4AT can support both delirium detection and baseline cognitive ascertainment in routine care, and our recent Age and Ageing paper suggests that abnormal 4AT scores may also identify patients who warrant cognitive follow-up even when delirium is not diagnosed [12].
Cite this study APA, Vancouver, BibTeX · download .bib or .ris
APA 7th
Penfold, R., & MacLullich, A. M. J. (2026). Delirium: more than a marker of baseline vulnerability. Age and Ageing. https://doi.org/10.1093/ageing/afag139
Vancouver
Penfold R, MacLullich AMJ. Delirium: more than a marker of baseline vulnerability. Age and Ageing. 2026. doi:10.1093/ageing/afag139. PMID: 42153717.
BibTeX
@article{penfold2026-42153717,
author = {Penfold, Rose and MacLullich, Alasdair M. J.},
title = {{Delirium: more than a marker of baseline vulnerability}},
journal = {Age and Ageing},
year = {2026},
doi = {10.1093/ageing/afag139},
pmid = {42153717},
url = {https://doi.org/10.1093/ageing/afag139}
}
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
- Across several cohorts, delirium is emerging as an important prognostic signal, independent of chronic markers of baseline morbidity, that identifies patients at markedly increased risk of death or future dementia.
- Delirium was associated with substantially higher 90-day mortality overall [adjusted hazard ratio (HR) 3.45], but the strongest relative association was actually in those without baseline dementia (HR 4.40).
- In the DELPHIC population-based cohort, Tsui et al. showed that higher baseline cognition was associated with lower delirium risk , but if delirium occurred, it was often more severe and associated with greater future cognitive decline [4].
- In a large acute general medicine cohort with long-term follow-up, Gan et al. reported that delirium was associated with prolonged admission, greater discharge care needs and increased mortality, with relatively more adverse outcomes in younger older adults (aged 65–74 years) without comorbid dementia [5].
- In a population-based cohort of 23 558 older adults without pre-existing dementia, we observed a similar pattern: delirium was associated with higher 30-day mortality risk across the spectrum of long-term conditions [6].
Why it matters
This paper reports across several cohorts that delirium is associated with markedly increased risk of death or future dementia, independent of baseline morbidity. The strongest relative associations were often in those without baseline dementia or with few long-term conditions.
Study details
- Study designcohort study
- Participants2,556
- Effect sizeHR 4.40; HR 2.22
- 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 randomised / 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 | 3 / 4 | 2,556 participants |
| Effect reported | 3 / 3 | Effect reported with a statistic (interval, p-value, ratio or similar) |
| Studied in people | 3 / 3 | Studied in people (participant count stated) |
| Randomised / blinded | 0 / 2 | No randomisation or blinding stated — scores zero (not stated in the record — scored 0) |
| Times cited | 1 / 7 | Cited 1 times (OpenAlex, 2026-10-10) |
| Citations per year | 0 / 5 | 0.5 citations a year over 2 year(s) since 2026 |
| Impact for its field and year | 3 / 6 | Cited 5.6× 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 1 times in 2024–2026 (2026 still in progress; OpenAlex) |
| Senior author's track record | 3 / 4 | Last-listed author Alasdair M. J. MacLullich: h-index 62 (OpenAlex, whole career) |
| Institution's track record | 1 / 3 | University of Edinburgh: institution h-index 1,378 (OpenAlex) |
| Multi-centre collaboration | 0 / 3 | OpenAlex lists 1 institution(s) in 1 country — scores zero (affiliation lists can be incomplete) |
| Indexed in PubMed | 2 / 2 | Indexed in PubMed (PMID 42153717) |
| Free to read | 2 / 2 | Free to read |
| Total | 55 / 100 | — |
What each of these 20 components measures, and what this score is not →
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