Frequency of delirium and its associated factors among COVID-19 inpatients in Iran

Background and aim: Delirium has been presented as the leading cause of sudden change in the mental state of patients with coronavirus disease 2019 (COVID-19). Given that the delayed diagnosis of such a dysfunction is often associated with excess mortality, it seems essential to devote vastly more attention to this significant clinical characteristic.

Materials and methods: This cross-sectional study was performed on 309 patients [viz. 259 cases hospitalized in general wards and 50 individuals admitted to the intensive care unit (ICU)]. For this purpose, a Demographic-Clinical Information Questionnaire, the Confusion Assessment Method (CAM), the Confusion Assessment Method for the ICU (CAM-ICU), the Richmond Agitation-Sedation Scale (RASS) and face-to-face interviews were completed by a trained senior psychiatry resident. The data analysis was further done with the SPSS Statistics V22.0 software package.

Results: Out of 259 patients admitted to the general wards and 50 cases in the ICU due to COVID-19, 41 (15.8%) and 11 (22%) individuals were diagnosed with delirium, respectively. As well, a significant relationship was observed between the incidence rate of delirium and age (p < 0.001), level of education (p < 0.001), hypertension (HTN) (p = 0.029), a history of stroke (p = 0.025), a history of ischemic heart disease (IHD) (p = 0.007), a history of psychiatric disorders, a history of cognitive impairment (p < 0.001), use of hypnotic and antipsychotic medications (p < 0.001) and a history of substance abuse (p = 0.023). Among 52 patients with delirium, only 20 cases had received psychiatric consultation by consultation-liaison psychiatry service for the possibility of delirium.

Conclusion: In view of the high frequency of delirium among COVID-19 inpatients, their screening for this important mental state should be a priority in clinical settings.