Exploratory Analysis of Out-of-Hospital Days Based on Cancer Patients in China

Cancer (re)admission time interval, or Out-of-Hospital Days (OHD) between two consecutive hospital (re)admissions, is commonly considered as an indicator of health service quality. Despite its importance, the risk factors of OHD are largely unknown because of limited access to cancer patients' data and the lack of relevant characteristics (e.g., geographic factors) in the data. To explore the association between patients' conditions and readmission events, we analyze a sample of 22,231 admissions (OHD>30), consisting of demographic, medical, and financial factors, extracted from Electronic Health Records (EHR) of 635,261 cancer patients from 190 hospitals in China. Geographic factors are also included by applying text mining to the free-form address fields of patient's homes and hospitals. Using hierarchical linear regression, we find that various factors significantly influence OHD: age, marital status, number of admissions, and whether the treating hospital is in the same province as the patient's home address.