Objectives:
The aim of the study was to determine general and specific in-hospital mortality rates, and to identify mortality risk factors.

Methods:
The study included 15,997 medical records of subjects who have been hospitalized at the Hospital for Patients with Neurotic and Psychiatric Diseases in Starogard Gdanski in 2005–2012. The study was designed as aretrospective cohort study with Cox proportional model for survival analysis. Standardized mortality ratio (SMR) and its 95% confidence intervals were calculated (95% CI).

Results:
Independent risk factors for death were: male sex, older age, hypertension, atherosclerosis, history of myocardial infarction, heart failure, cirrhosis, tuberculosis, history of cancer, anemia, and inflammation. Delirium not induced by alcohol or other psychoactive substances was associated with the highest mortality risk of all psychiatric diagnoses. Unemployment was associated with doubled risk of in-hospital death. SMR for the whole population of hospitalized patients amounted to 17.88 (95% CI: 15.99–20.00).

Conclusions:
Medical comorbidities have a significant and clinically important impact on in-hospital mortality in psychiatric patients in Poland. Clinicians’ awareness and active management of medical conditions amongst such patients is needed to reduce the risk of inhospital mortality in psychiatric facilities.