3833 Ascertainment of delirium in older adults presenting to a primary care out of hours (OOH) service: a retrospective cohort study

Abstract Introduction Out-of-hours (OOH) services provide emergency primary care outside normal GP hours, serving patients with higher health needs. Delirium affects 25% of hospitalised older adults, causes distress to patients and carers, and leads to poor outcomes. However, little is known about delirium presentations and prevalence in OOH services. We aimed to investigate delirium occurrence and management using case records from an OOH service in South-West England. Methods The OPEN database contains 33,345 consultations of patients ≥65 attending the OOH service between April 2019–March 2020. We screened consultations for delirium symptoms during April and July 2019, and January 2020. Records were reviewed by two GPs independently using DSM-V criteria to identify probable or possible delirium. We validated our search strategy by reviewing a random sample of 100 consultations initially classified as ‘search-negative’ and assessed inter-rater reliability. Patient characteristics were compared using Chi-squared tests. Results Of 4288 consultations with patients ≥65 in the study periods, 394 (9.2%) involved possible or probable delirium. A further 76 (1.8%) had end-of-life delirium and were excluded from further analysis. Patients with delirium were similar in age to those without, but more likely to live in residential care (29% vs. 14%, p < 0.001) and have dementia (46% vs. 11%, p < 0.001). 67% of delirious patients required home visits, compared to 22% without delirium (p < 0.001). Delirium was not available as a coded diagnosis; only 6% of cases were coded as ‘Acute Confusion,’ whilst 20.9% were coded ‘Urinary Tract Infection.’ Patients with delirium were admitted to hospital twice as often as those without (21% vs 10%, p < 0.001). Conclusions Delirium is a common OOH presentation, representing ~10% of consultations with patients ≥65. These patients often have cognitive impairment, require home visits, and are more likely to be hospitalised. Improved recognition and coding could support better management and service planning.