10-year Trends in Diagnostic Stability and Distribution among Psychiatric Inpatients in a General Hospital in China

Abstract Purpose： To evaluate the diagnostic stability between admission and discharge of psychiatric inpatients in a general hospital, as well as to assess the distribution of diseases in the sample over the past decade. Methods: A total of 20,359 psychiatric inpatients were included in this retrospective study from June 2011 to December 2020. The short-term diagnostic consistency was evaluated by comparing their first admission and discharge diagnoses. Readmission patients' first and last discharge diagnoses were also compared to analyze the relatively long-term diagnostic stability. Demographic and clinical characteristics were analyzed to identify predictors of diagnostic discrepancy during hospitalization. Results: From 2011-2020, for all psychiatric inpatients, the average length of stay decreased from 22 days to 17 days. The hospitalization rate decreased from 42.4% to 20.7% for schizophrenia and grew from 13.8% to 25.5% for depression. Diagnoses were retained by 92.6% of patients at their first discharge diagnosis, ranging from 100% for disorders of psychological development to 16.3% for unspecified mental disorders. Most diagnostic conversions were to bipolar disorder and schizophrenia. However, among rehospitalizations, the diagnostic stability notably dropped to 71.3%. For rehospitalizations, mood disorders and schizophrenia spectrum disorders were relatively stable diagnoses categories, with 72.7%-76.7% of patients receiving the same diagnosis, although results of specified diagnoses within these categories ranged from 5.9% to 91%. Length of hospitalization and age were associated with the diagnosis alterations. Conclusion: Even though the diagnosis of mental disorders was stable in short hospitalizations, maintaining longitudinal and long-term consistency of diagnosis still requires more effort.