Huang KHG, et al. - In hematologic malignancy inpatients requiring systemic antibiotics, researchers delineated the impact of reported beta-lactam (BL)-only allergy (BLOA) label on clinical outcomes compared to those with no BL allergy (NBLA). In this study, observations revealed worse clinical outcomes and higher healthcare cost for patients with reported BL allergy than those without BL allergy label.

Methods

• At two tertiary care hospitals, researchers performed a retrospective cohort study of adult inpatients with hematologic malignancy from 2010 to 2015.
• Hospital length of stay (LOS) after first antibiotic was observed as the primary outcome.
• Re-admission, mortality, complications, total hospital charges, and antibiotic usage were assessed as secondary outcomes.

Results

• In this cohort (n=4671), researchers identified leukemia in 38.3%, Hodgkin’s lymphoma in 4.9%, non-Hodgkin’s lymphoma in 36.1% and multiple myeloma in 20.7%.
• Antibiotic allergy was noticed among 35.1%; 14.1% (n=660) reported BLOA (including 9.3% with penicillin-only allergy and 3.3% cephalosporin-only allergy).
• Longer median LOS for subjects with BLOA compared to NBLA was reported(11.3 vs 7.6 days, p < 0.001), which remained significant after multivariable adjustment.
• Patients with BLOA vs NBLA also indicated markedly worse outcomes in terms of mortality rate at 30-days (7.6% vs. 15.8%, p=0.017) and 180-days (15.8% compared to 12.2%, p=0.013), 30-day re-admission rate (19.2% vs. 15.1%, p=0.008), Clostridium difficile rate (17.7% vs. 11.6%, p < 0.001), total hospital charges ($223046 vs. $173256, p < 0.001), antibiotic classes used (median 3 vs. 2 classes/patient, p < 0.001), and antibiotic duration (median 9.0 vs. 6.0 days, p < 0.001).