Abstract
Objective: Delirium is a significant condition that is frequently encountered in elderly inpatients and leads to serious consequences. It is frequently underrecognized, especially by non-psychiatrist physicians, leading to delays in treatment and worsened clinical outcomes. This study aimed to assess how accurately non-psychiatrist physicians recognize delirium in elderly patients and to explore the diagnostic concordance between psychiatrists and non-psychiatric physicians. Additionally, it sought to identify specific sociodemographic, clinical, and psychiatric factors—such as delirium subtype and timing of consultation—that contribute to missed or inaccurate diagnoses.
Methods: We conducted a retrospective record review of patients aged 65 years and older who were hospitalized at a tertiary university hospital from 2020 to 2023 and received psychiatric consultations. Of 1718 patients, 344 were diagnosed with delirium following a psychiatric assessment. Data regarding sociodemographic and clinical characteristics, including duration of hospitalization, consultation timing, medical diagnoses, treatment methods, and psychiatric history, were collected. A binary logistic regression model was utilized to evaluate the relationship between these variables and the accuracy of delirium diagnosis.
Results: The study sample consisted of 344 elderly patients, with a mean age of 79 years. The patient population consisted of 194 (43.6%) men and 150 (56.4%) women. Of these, 11.9% were diagnosed with hypoactive delirium and 88.1% with hyperactive delirium. A total of 68.9% of delirium cases were initially missed by non-psychiatrist physicians. In consultations with a diagnosis of hypoactive delirium, depression (34.1%), anxiety disorder (4.9%) or mood disorder (9.8%) were cited as reasons for consultation instead of delirium. The results indicated that hypoactive delirium was significantly more likely to be missed compared to hyperactive delirium (p=0.005). Logistic regression analysis revealed that both the type of delirium and the duration until psychiatric consultation were significant predictors of missed diagnosis (OR = 0.31 and OR = 1.99, respectively).
Conclusion: The findings highlight the challenge of diagnosing delirium—especially the hypoactive subtype—by non-psychiatrist clinicians. Prolonged hospitalization before consultation was also associated with higher rates of missed diagnosis. These results underline the need for targeted education and training to improve early recognition of delirium in elderly inpatients.

Key words: Consultation, Delirium, Elderly Patients, Missed Diagnosis