Changes in inpatient admissions before and during COVID-19 outbreak in a large tertiary hospital in Shanghai

Background: The coronavirus disease 2019 (COVID-19) outbreak caused a significant strain on healthcare resources and utilization worldwide. However, the impact of COVID-19 outbreak on patient hospitalization was barely known. This study aimed to determine the impact of the outbreak on the pattern of inpatient hospital admissions to help allocate health care resources during a pandemic. Methods: This retrospective study included patients who were hospitalized in a tertiary teaching hospital in Shanghai between 1 January and 30 April across the years 2017 to 2020. The number of hospitalizations during the study period from 2017 to 2020 were 30,605, 31,464, 32,812 and 24,163, respectively. Changes in patient volumes and the frequency of the International Classification of Diseases and Related Health Problem Tenth Edition (ICD-10) codes before and after the onset of the COVID-19 outbreak were analyzed and presented as absolute and relative differences with 95% confidence intervals between periods of different years. Results: Overall inpatient hospital admissions decreased by 26.35% between January and April 2020, compared to the same period in 2019. The average age of patients in 2020 was higher compared to those from 2017 to 2019. Conversely, the proportions of self-paying patients and non- local patients were significantly lower between January and April 2020 compared to the same period in the previous three years. The top five ICD-10 codes remained common before and during the pandemic. Admissions associated with antineoplastic radiation therapy, chemotherapy, and immunotherapy increased in frequency and proportion by 2020 (difference, 5.6%, 95% CI: 4.4% to 6.8%), and increased proportions were observed for liver and intrahepatic bile duct malignancies (2.18%, 95% CI: 1.15% to 3.21%), cerebral infarction (2.27%, 95% CI: 0.54% to 4.00%), and chronic kidney disease (3.56%, 95% CI: 1.79% to 5.33%). Conclusions: There was a significant reduction in the number of inpatients and a marked change in admission diagnoses during the COVID-19 outbreak. Our findings are useful for making informed decisions on hospital management and reallocation of available health care resources during a pandemic.