The clinical and economic impact of reported beta-lactam allergy in hospitalized patients with hematological malignancy

Abstract

Background: Patients with hematologic malignancies are vulnerable to developing infections during hospitalization. Up to 21% of these patients report an allergy to beta-lactam antibiotics. The clinical and economic consequences of beta-lactam allergies (BLA) in this population remain understudied. Objective: The aim of this study was to describe the healthcare resource utilization and clinical outcomes in hospitalized patients with acute leukaemia who have a reported BLA. Design: Single-centre, retrospective cohort study Setting: Tertiary cancer centre in Toronto, Ontario Patients: Adult patients hospitalized with a primary diagnosis of acute leukaemia Methods: Patients with a reported BLA were compared to those without. The primary outcome was antibiotic use and secondary outcomes included hospitalization cost, hospital length of stay (LOS), clostridium difficile infection (CDI) rate, colonization with a multidrug resistant organism and inpatient mortality rate. Antibiotic use and hospitalization cost were analysed using multivariable negative binomial regression and generalized linear models, respectively. Results: A total of 628 patients were included; 9.4% had a reported BLA. Among patients, 74.7% had acute myeloid leukaemia and 20.9% had acute lymphoblastic leukaemia. Nearly half the cohort (41.2%) received hematopoietic stem cell transplants. After adjusting for covariates, antibiotic use was 11% lower (IRR=0.89, 95% CI=0.69-1.16, p=0.395) and hospitalization cost was 7% higher (95% CI=0.85-1.34, p=0.549) in the BLA cohort. These patients also had numerically longer median LOS, lower rates of CDI and mortality, and higher rates of colonization with methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus compared to those without a BLA. Conclusions: The prevalence of BLA in this Canadian population of hospitalized patients with acute leukaemia and a self-reported BLA was lower than what is currently reported in the literature. Antibiotic use and hospitalization costs were not statistically different between groups. Future studies are needed to further evaluate these findings.