Predictors of chemotherapy-related unplanned acute care in outpatients receiving oral anticancer drugs.

Severe adverse reactions to outpatient chemotherapy receiving oral anticancer drugs often lead to unplanned acute care (UAC) requirements, including unscheduled emergency visits and hospitalizations. These events result in treatment delay or interruption, which reduces the patients' willingness to continue treatment and negatively impacts their quality of life. The aim of this study was to identify predictive factors for UAC, helping promote safer outpatient chemotherapy through early intervention. A retrospective case-control study was conducted with patients receiving outpatient chemotherapy with oral anticancer drugs at the National Cancer Center Hospital East between April 1, 2020, and March 31, 2021. Patients who experienced UAC were identified as cases, and matched controls were selected from those who did not experience UAC. Conditional multivariate logistic regression analysis was performed to estimate adjusted odds ratios and 95% confidence intervals to examine the association between risk factors and UAC onset. Among cytotoxic drug users, increased blood urea nitrogen concentration and decreased serum sodium concentration were identified as factors associated with increased UAC risk. In molecular-targeted drug users, increased blood creatinine concentration was associated with increased UAC risk. These findings may help optimize patient management and reduce UAC rates in outpatient chemotherapy settings.