The association of comorbid depression with intensive care unit admission in patients with diabetes: a prospective cohort study.

Background: It is unknown if comorbid depression in patients with diabetes mellitus increases the risk of intensive care unit (ICU) admission.

Objective: This study examined whether comorbid depression in patients with diabetes increased risk of ICU admission, coronary care unit (CCU) admission, and general medical-surgical unit hospitalization, as well as total days hospitalized, after controlling for demographics, clinical characteristics, and health risk behaviors.

Method: This prospective cohort study included 3,596 patients with diabetes enrolled in the Pathways Epidemiologic Follow-Up Study. We assessed baseline depression with the Patient Health Questionnaire-9. We controlled for baseline demographics, smoking, BMI, exercise, hemoglobin A(1c), medical comorbidities, diabetes complications, type 1 diabetes, diabetes duration, and insulin treatment. We assessed time to any ICU, CCU, and/or general medical-surgical unit admission using Cox proportional-hazards regression. We used Poisson regression with robust standard errors to examine associations between depression and total days hospitalized.

Results: Unadjusted analyses revealed that baseline probable major depression was associated with increased risk of ICU admission [hazard ratio (HR) 1.94, 95% confidence interval (95% CI)(1.34-2.81)], but was not associated with CCU or general medical-surgical unit admission. Fully adjusted analyses revealed probable major depression remained associated with increased risk of ICU admission [HR 2.23, 95% CI(1.45-3.45)]. Probable major depression was also associated with more total days hospitalized (Incremental Relative Risk 1.64, 95%CI(1.26-2.12)).

Conclusions: Patients with diabetes and comorbid depression have a greater risk of ICU admission. Improving depression treatment in patients with diabetes could potentially prevent hospitalizations for critical illnesses and lower healthcare costs.