Variation in Evaluation and Management of Febrile Infants 61 to 90 Days Old

To describe trends and variation in testing, treatment, and disposition of febrile infants aged 61-90 days evaluated in US emergency departments (EDs).

For this retrospective cohort study, we included noncritically ill, previously healthy infants aged 61-90 days with temperatures ≥ 38°C evaluated at 12 Pediatric Emergency Care Applied Research Network Registry EDs during 2017-2023 (trends analysis) and 17 EDs in 2022-2023 (variation analysis). Outcomes included urine, blood, cerebrospinal fluid, and respiratory viral testing; antibiotic administration; hospitalization; and invasive bacterial infections.

We included 9041 infants in the trends analysis and 4448 in the variation analysis. From 2017-2023, urine testing (53.8% to 45.7%; P < .01), blood cultures (35.0% to 18.9%; P < .01), cerebrospinal fluid testing (3.8% to 1.1%; P < .01), hospitalizations (22.6% to 16.9%; P < .01), and parenteral antibiotics (10.2% to 5.8%; P < .01) decreased. Conversely, respiratory viral testing (13.4% to 63.3%; P < .01) and procalcitonin use increased (1.6% to 14.2%; P < .01). In 2022-2023, a median 46.3% of infants had urine testing (range: 32.2%-73.9% across hospitals), 21.1% had blood cultures (range: 8.0%-51.1%), and 16.2% were hospitalized (range: 7.9%-26.1%). Respiratory viral testing (median 71.8%; range: 34.7%-95.5%) and procalcitonin use (median 13.4%; range: 0%-37.0%) also varied. The prevalence of invasive bacterial infections was similarly low across hospitals (median 0.3%; range: 0%-1.2%).

There has been significant change over time in testing and disposition of febrile infants aged 61-90 days, although with substantial interhospital variation. Implementation of decision support tools is needed to standardize management and reduce practice variations.