[Association between psychiatric comorbidities and hospital length of stay in post-emergency internal medicine patients].

Introduction: Patients with psychiatric disorders suffer from a higher rate of somatic disorders than those without psychiatric disorder, often inappropriately managed. Our study aimed to describe patients with psychiatric comorbidity in post-emergency internal medicine units and to compare their length of hospital stay to patients without psychiatric disease.

Methods: This French cross sectional study used the data warehouse of the greater Paris hospitals. It included, all patients hospitalized through the emergency department in 9 internal medicine departments during the year 2017. Psychiatric disorders and the burden of somatic disorders (Charlson score) were determined through diagnostic coding. Charlson score and hospital length of stay were compared between patients with and without psychiatric comorbidity.

Results: In total, 8981 hospital stays (8001 patients) were included, 1867 (21%) with psychiatric comorbidity. After adjusting for age, gender, hospital and main diagnosis, the Charlson score was on average 0.68 higher in the psychiatric comorbidity group (P<0.001) and the length of hospital stay was 30% higher after further adjustment on the Charlson score (P<0.001). These differences were consistent for each main diagnosis.

Conclusion: Patients with psychiatric comorbidity are frequent in post-emergency internal medicine wards. They experience longer hospital stays, only partly related with a higher burden of somatic disorders. Special attention should be paid to this vulnerable population.