Associations between psychiatric comorbidity and intensive care unit length of stay, hospital length of stay, and in‐hospital mortality: A retrospective observational study

Aim: Psychiatric comorbidities are common among patients admitted to the intensive care unit (ICU), but findings regarding their impact on clinical outcomes remain inconsistent. Additionally, existing studies have often included patients admitted for suicide attempts or self-harm, leaving insufficient evidence about the independent effects of psychiatric comorbidity on clinical outcomes. To address this gap, this study investigated the independent association of psychiatric comorbidity with ICU length of stay, hospital length of stay, and in-hospital mortality among patients admitted to the ICU, excluding those admitted for suicide attempts or self-harm. Methods: Of the 2599 patients admitted to the ICU of a university hospital, 2192 were included in the analysis. After adjusting for age, sex, body mass index, admission category, and severity score, generalized linear models were used to evaluate ICU and hospital length of stay, and logistic regression analysis was used to assess in-hospital mortality. Results: Among the 2192 patients included in the analysis, 75 had psychiatric comorbidity. In adjusted analyses, psychiatric comorbidity was not significantly associated with ICU length of stay, hospital length of stay, or in-hospital mortality. Conclusion: No participants were admitted to the ICU for suicide attempts or self-harm, and psychiatric comorbidity was not an independent predictor of ICU length of stay, hospital length of stay, or in-hospital mortality. Thus, in this ICU population, no statistically significant association was detected between psychiatric comorbidity and short-term clinical outcomes. Therefore, caution is needed when estimating ICU outcomes based solely on the presence of psychiatric comorbidity.