Abstract
Background: Regularly monitoring mortality rates among psychiatric inpatients is essential for evaluating the effectiveness of healthcare services and subsequently improving healthcare delivery. Prior research in Nigeria focused on psychiatric hospitals, and no published data exist on inpatient psychiatric mortality in Nigerian teaching hospitals. This study aimed to investigate mortality and its associated factors among inpatients admitted to the psychiatric unit of a teaching hospital in Nigeria.

Methods: A register-based descriptive retrospective design was used for this study. Review of the records of all patients who died while on admission between 1977 and 2017 was carried out.

Results: Among 6490 admissions to the psychiatric unit over 40 years, 46 patients (0.71%) died during their admission, resulting in a mortality rate of 1.15 deaths per year. The age of death ranged from 18 to 90 years, with an average of 48.8 years (standard deviation 18.5). Females comprised a larger proportion of deaths (76.1%, M
ratio = 1:3.2). Psychotic disorders were the most frequent diagnoses (35.0%), with acute psychosis being the most common (25.0%), followed by depression (20.0%). Notably, a higher proportion of patients with organic disorders (75.0%) died within two weeks of admission compared to those with non-organic disorders (61.5%).

Conclusion: This 40-year study at a Nigerian teaching hospital revealed a low mortality rate (0.71%) for psychiatric patients. Females had a higher mortality rate than males, and most deaths occurred within the first two weeks of admission, particularly for patients with organic diagnoses. Psychotic disorders were the most prevalent diagnoses, followed by depression and bipolar disorder. These findings highlight the need for enhanced early identification and intervention strategies for high-risk patients.

Key words: mortality, psychiatry, inpatients, teaching hospital