Incidence and cost of adverse drug reactions in a French cancer institute

Objectives: The incidence and the cost of adverse drug reactions (ADR) in patients treated by cancer chemotherapy were assessed using hospital database records from 1993 in a French regional cancer institute. Methods: Patients with ADRs were identified using a list of ICD-9 codes describing potential adverse events. Direct medical costs for treating these ADRs were assessed according to the hospital system of claims data. Results: Among the 3429 in-patients hospitalized in 1993, we found 171 patients (5% of the population) who presented at least one ADR (3.5% of the total number of hospital stays). A total of 313 ADRs occurred in 256 hospital stays (3.5% of the hospital stays in 1993). Of the patients with ADRs 60.2% were female and their mean age was 51.5 years; 106 patients presented with at least one ''serious'' ADR according to the WHO definition. These ADRs occurred during 130 hospitalizations. In 7 cases, ADRs led to death. There was no relationship between age or sex and the seriousness of the ADR. Of the ADRs 91% was type ''A'' (predictable). We estimated that the cost of ''serious'' ADRs was 1.8% of the global budget of the hospital. The average cost of ADRs leading to hospitalization was 33 037 French Francs at the current rate in 1993. This cost represented an additional cost of 32% of the overall cumulative yearly cost per patient in the institution. Conclusion: This study emphasizes the medical and economic impact of the management of ADR in anticancer treatments.