Comparing febrile children presenting on and off antibiotics to the emergency department: a retrospective cohort study

Background It is not yet known how antibiotics may affect Serious Bacterial Infections (SBI). Our aim is to describe the presentation, management, and serious bacterial infections (SBI) of febrile children on or off antibiotics. Methods Retrospective, cohort study of febrile Emergency Department patients, 0-36 months of age, at a single institution, between 2009and 2012. Results Seven hundred fifty-three patients were included: 584 in the No-Antibiotics group and 169 (22%) in the Antibiotics group. Age and abnormal lung sounds were predictors for being on antibiotics (OR 2.00 [95% CI 1.23-3.25] and OR 1.04 [95% CI 1.02-1.06] respectively) while female gender, and lower temperatures were negative predictors (OR 0.68 [95%0.47-0.98] and OR 0.47 [95% CI 0.32-0.67] respectively). Antibiotics were prescribed by a physician 89% of the time; the most common one being Amoxicillin/Clavulanic Acid (39%). The antibiotic group got more blood tests (57% vs 45%) and Chest X-Rays (37% vs 25%). Overall, the percent of SBIs (and pneumonias) was statistically the same in both groups (6.5% in the No-antibiotic group VS 3.6%). Conclusions Children presenting on antibiotics and off antibiotics were significantly different in their presentation and management, although the overall percentages of SBI were similar in each group. Further investigations into this subgroup of febrile children are needed.