- Background Delirium, a common problem among hospitalized elderly patients, is not usually diagnosed by doctors for various reasons. The primary aim of this study was to evaluate the effect of a short training course on the identification of delirium and the diagnostic rate of delirium among hospitalized patients aged ≥65 years. The secondary aim was to identify the risk factors for delirium. Methods A prospective study was conducted in an acute-care hospital in Moscow, Russia. Six doctors underwent a short training course on delirium. Data collected included assessment by the confusion assessment method for the intensive care units, sociodemographic data, functional state before hospitalization, comorbidity, and hospitalization indices (indication for hospitalization, stay in intensive care unit, results of laboratory tests, length of hospitalization, and in-hospital mortality). Results Delirium was diagnosed in 13 of 181 patients (7.2%) who underwent assessment. Cognitive impairment was diagnosed more among patients with delirium (30.0% vs 6.1%, P=0.029); Charlson comorbidity index was higher (3.6±2.4 vs 2.3±1.8, P=0.013); and Barthel index was lower (43.5±34.5 vs 94.1±17.0, P=0.000). The length of hospitalization was longer for patients with delirium at 13.9±7.3 vs 8.8±4.6 days (P=0.0001), and two of the 13 patients with delirium died during hospitalization compared with none of the 168 patients without delirium (P=0.0001). Conclusion Although the rate of delirium was relatively low compared with studies from the West, this study proves that an educational intervention among doctors can bring about a significant change in the diagnosis of the condition.