Delirium clinical correlates and underdiagnosis in a skilled nursing home

Background and objectives: There is scarce research about delirium risk factors in nursing homes (NH). Our objective was to evaluate in a single day the association of different clinical aspects with delirium in a NH. Methods: We evaluated all patients hospitalised in a NH. We used a bivariate analysis and performed a logistic regression on significantly different characteristics between groups. Results: We assessed 131 patients and 30 (22.1%) met DSM-5 criteria for delirium. Only 3 of them were already diagnosed on their medical records by treating physicians, and only one by the nurses. The variables retained in the conditional logistic analysis were: age (OR 1.08, 95%CI 1.01–1.15), widowhood (OR 3.70, 95%CI 1.13–12.09), need of physical restraints (OR 9.22, 95%CI 2.39–35.52) or intravenous catheter during the previous 24 h (OR 46.02, 95%CI 4.95–427.58), hearing impairment (OR 4.26, 95%CI 1.35–13.38), and a main active diagnosis of systemic infection (OR 3.01, 95%CI 0.93–9.71). All of them were significantly related to delirium (p < 0.05), except for systemic infection (p = 0.065). Unexpectedly, dementia was not retained within the model. Conclusions: Treating staff underdiagnosed delirium. Delirium was associated with some clinical factors previously described in acute and post-acute medical units. However, the lack of association with known risk factors like dementia, that is very frequent in NH, and relationship with new ones explored, like widowhood, points to the need for further research into the particularities and basal characteristics of NH patients, and for standardisation of the assessment of some critical variables and of delirium itself.