Unrecognized Delirium is Prevalent among Older Patients Admitted to General Medical Wards and Lead to Higher Mortality Rate

Delirium is a syndrome associated with high mortality that often goes undetected by healthcare providers. There has been limited evidence regarding the consequences of under-recognition of delirium on patient outcomes. The present study aimed to investigate the rate of under-recognized delirium and explore the effect of unrecognized delirium on patient mortality. A cohort of older patients aged 70 years or more who developed delirium during admittance to general medical wards at Siriraj Hospital between January and March 2009 was retrospectively investigated. A diagnosis of delirium was made by geriatricians applying DSM-IV criteria. Medical records were reviewed to identify recognition of delirium by physicians and nurses. Factors affecting mortality were investigated using univariate and multivariate logistic regression models. Of 110 patients who developed delirium, 57.3% of cases were identified as delirium by physicians, with only 14.5% of cases having their delirium documented in the discharge summary. Rate of delirium recognition among nurses was 61.8%, with a comprehensive nursing care plan developed in only 13.6% of cases. Patients with delirium that went unrecognized by attending physicians had a mortality rate of 38.3%, compared to 15.9% for the recognized delirium group (p = 0.008). In multivariate analysis, unrecognized delirium was identified as an independent risk factor for death with adjusted OR of 5.16 (95% CI 1.45-18.29). Rate of unrecognized delirium by healthcare providers in this study was high, but comparable to previous studies. Moreover, under-recognition of delirium was found to lead to higher mortality. Routine screening for delirium and implementation of a proactive care plan by nurses for older patients admitted to general medical wards might be a strategy for improving this common and preventable medical condition and for lowering delirium-related mortality rates.