Drug-related problems and risk factors related to unplanned hospital readmission among cancer patients in Belgium

Introduction There are about 60,000 diagnoses of cancer per year in Belgium. After hospital care, about 12-13% of cancer patients are readmitted within 30 days after discharge. These readmissions are partly related to drug-related problems (DRP), such as interactions or adverse drug effects (ADE). Objectives The aim of this study is to quantify and to classify DRP readmissions within 30 days for cancer patients and to highlight risk factors potentially correlated to readmissions. Methods This study is a 6-month observational retrospective study in two care facilities in Brussels: an academic general hospital and an academic oncology center. Patients readmitted within 30 days after their last hospital care for a potential DRP were included. Patient files were evaluated with an intermediate medication review that included interactions analysis (Lexicomp (R)). The probability of DRP readmission was assessed using the World Health Organization's Uppsala Monitoring Centre (WHO-UMC) system. Results The final population included 299 patients; among them, 123 (41.1%) were readmitted due to DRP (certain DRP (4.9%), probable DRP (49.6%), and possible DRP (45.5%)). Risks factors linked to these DRP were a low Charlson Comorbidity Index, polypharmacy, the kind of hospital, and some chemotherapies (platinum preparations). Among all readmitted patients, the D-type interactions were the most common (44.8%), which suggest a possible therapy modification. However, around 10% of interactions were X-type (drug combination to avoid). Conclusion Almost 10% of patient readmitted within 30 days were potentially related to a DRP, most of them from adverse drug effects. Four risk factors (low Charlson Comorbidity Index, polypharmacy, the hospital, and some chemotherapies) were highlighted to prevent these readmissions.