Sources of practice variation in febrile infants aged 8–60 days: a multi-level analysis

Background Management decisions for febrile infants vary greatly, with knowledge gaps in identifying sources of practice variation. Thus, we estimated proportions of total and age-stratified (8–28, 29–60 days) variation in hospitalization and lumbar puncture procedures contributed by patient (infant)-, physician-, and hospital-level factors. Methods Retrospective cohort study of febrile infants aged 8–60 days seen in emergency departments in New York State from January 2012 to July 2021. We constructed a three-level multi-level logistic regression model with random effects for physician and hospital levels to partition total and age-stratified variation in hospitalizations and lumbar puncture procedures and adjusted for covariates at each level. Results Of 35,756 febrile infants,18,124 were hospitalized (49%) and 12,959 received a lumbar puncture (36%). Adjusted models showed physician- and infant-level factors contributed the most to variation in hospitalization (59.3%) and lumbar puncture management decisions (81.9%), respectively. Hospital-level factors accounted for >10% of variation in hospitalizations and ~10% of variation in lumbar punctures. Hospital-level variation did not differ significantly by age. Conclusions Findings show divergent practice variation sources for hospitalization (physician-level) and lumbar puncture (infant-level). Hospital-level factors account for a non-negligible proportion of practice variation, representing opportunities to identify targeted interventions to reduce practice variation. Impact Management decisions for febrile infants aged 8 to 60 days vary greatly Little is known about sources of practice variation that may be modifiable In this population-based cohort study, physician- and infant-level factors contributed the most to variation in hospitalization and lumbar puncture Hospital-level factors accounted for at least 10% of variation in hospitalizations and lumbar punctures Findings inform future hospital-level intervention studies.