Objective  To study the status quo of the readmission of senile dementia patients in Chengdu, and to analyze the primary diagnosis, the economic burden and the influencing factors of readmission.

  Methods  Dementia inpatients aged 60 and above in Chengdu were the subjects of this study. The subjects were diagnosed with dementia between 2013 and 2017. Their heath insurance coverage was either the basic medical insurance for urban employees in Chengdu or the basic medical insurance for urban and rural residents of Chengdu. The rank sum test and the chi-square test were conducted to analyze the differences in readmission rate and the economic burden of hospitalization among subjects with different characteristics. Logistic regression was done to analyze the factors affecting readmission.

  Results  The total number of dementia inpatients over the 5-year period was 27881 patients (78820 admissions). The 30-day readmission rate was 25.14% (7011/27881) and the 5-year readmission rate was 45.79% (12767/27881). The primary diagnoses of 12767 readmitted patients mainly included dementia (28.57%), circulatory system diseases (24.26%), and respiratory system diseases (23.71%). The economic burden of hospitalization was higher for readmitted patients than that of patients who were not readmitted (Z=33.777, P<0.001). The occurrence of readmission was correlated to the following factors, advanced age (compared to that of the 60-65 yr. group, the 70-75 yr. group: odds ratio OR=1.123, 95% confidence interval CI: 1.019-1.237, and the 75-80 yr. group: OR=1.123, 95% CI: 1.108-1.218), participation in the basic medical insurance for urban employees (OR=1.674, 95% CI: 1.578-1.775), types of dementia (compared to unspecified dementia, Alzheimer's dementia group: OR=1.256, 95% CI: 1.163-1.357, Parkinson's disease dementia group: OR=1.774, 95% CI: 1.658-1.898, and mixed-type dementia group: OR=1.750, 95% CI: 1.457-2.103), disease condition (compared with patients with only dementia, those who have other diseases: OR=0.536, 95% CI : 0.493-0.583), length of hospital stay (OR=1.593, 95% CI: 1.552-1.635), and staying at a lower level hospital (compared to that of tertiary hospitals, secondary hospitals: OR=1.319, 95% CI: 1.248-1.395, primary hospitals: OR=1.744, 95% CI: 1.608-1.891, and other hospitals: OR=1.465, 95% CI: 1.311-1.537).

  Conclusion  Senile dementia patients have a high 30-day readmission rate, and the readmission entails heavy economic burdens on the patients. For the populations covered by medical insurance, the following features are correlated to the occurrence of readmission: advanced age, coverage by the basic medical insurance for urban employees, Alzheimer's dementia, Parkinson's disease dementia, mixed-type dementia, dementia patients without other comorbidities, extended length of stay, and hospitalization at a lower level hospital. However, further research is needed for better understanding of the specific mechanisms so that readmission of senile dementia patients can be reduced and the economic burden of the disease can be minimized.