Psychiatric comorbidity and in-hospital mortality in patients hospitalized for physical conditions in Germany

J Psychiatr Res. 2025 Jan 27:182:489-496. doi: 10.1016/j.jpsychires.2025.01.049. Online ahead of print.

Abstract

Objective: To investigate the association between psychiatric comorbidity and in-hospital mortality in patients hospitalized for physical conditions in Germany.

Methods: This retrospective study used data from the hospital database of IQVIA (Frankfurt, Germany). Adults with a psychiatric disorder as a secondary diagnosis at hospital admission were matched (1:3) to those without a psychiatric disorder using a propensity score based on age, sex, hospital department, and primary diagnosis. Diagnoses of psychiatric and physical disorders relied on the ICD-10 classification. Associations between psychiatric comorbidity and in-hospital mortality were studied using logistic regression.

Results: There were 36,796 patients with (mean [SD] age 66.2 [14.7] years; 53.4% men) and 110,388 patients without psychiatric comorbidity included in the study (mean [SD] age 66.1 [15.1] years; 51.9% men). Overall, no statistical association was observed between psychiatric comorbidity and in-hospital mortality (OR = 1.00, 95% CI = 0.95-1.05). However, there was a positive and significant relationship in people aged ≤70 years and men, whereas a negative association was observed for those aged >80 years and women.

Conclusions: Psychiatric comorbidity was associated with increased in-hospital mortality in patients aged ≤70 years and men in hospitals in Germany. Further research is warranted to corroborate these findings in other countries.

Keywords: Cross-sectional study; Epidemiology; Germany; Hospital mortality; Psychiatric comorbidity.