Delirium codelist creation

Author: Jaime Fanjul Iglesias 
Last updated: May 14, 2026 
Data source: CPRD Aurum (Medical Dictionary)

Codelist created for projects on community infections, dementia and health outcomes

Built using the CPRD Aurum Medical Browser, Version March 2026

1. Used the terms from the LSHTM delirium codelist as search terms (Coste, Astrid; Mansfield, Kathryn E. (2025). Clinical codelist - Delirium - CPRD Aurum. [Dataset]. London School of Hygiene & Tropical Medicine, London, United Kingdom. https://doi.org/10.17037/DATA.00004485)
2. Re-ran the search in the Medical Browser on the following terms: "delirium", "delirious", "confusional state", "acute confusional", "subacute confusional", "toxic confusional", "drug-induced delirium", "drug induced delirium", "acute confusion", "onset of confusion", "level of confusion"
3. Removed codes matching the overall exclusion terms applied to all codelists: "risk of", "trial", "FH:", "exposure", "candidate", "not seen", "pregnan*", "family history", "congenital", "neonatal", "vaccin*"
4. Removed specific non-diagnostic or irrelevant terms by exact match (full list in R script; see inclusion/exclusion criteria below)
5. De-duplicated on medcodeid
6. Reviewed all resulting codes from scratch against inclusion/exclusion criteria (below)
7. Reviewed by CWG, KM, MI, May 2026

Columns:
medcodeid	
Term

Notes on inclusion/exclusion criteria:
- Included codes for delirium (all forms), acute/subacute/toxic/drug-induced confusional states, and confusion with acute or sudden onset
- Excluded assessment and screening tools and scores (e.g. 4AT, Confusion Assessment Method (CAM), Abbreviated Mental Test Score, MMSE for confusion)
- Excluded prevention, care plan, care pathway/bundle and team review codes
- Excluded advice, information and leaflet codes
- Excluded risk codes and codes indicating delirium was ruled out (e.g. "At increased risk for delirium", "Delirium excluded")
- Excluded family history codes
- Excluded "Decreased level of confusion" (indicates improvement rather than a delirium episode)
- Excluded "Chronic confusional state" (not consistent with the acute nature of delirium)
- Excluded confusional migraine codes ("Confusional migraine of childhood", "Acute confusional migraine")
- Included alcohol/substance withdrawal delirium codes (e.g. delirium tremens)
- Included historic ("history of") codes