Determinants of Blood Culture Use in Critically Ill Children: A Multicenter Qualitative Study

Introduction:Blood cultures are fundamental in diagnosing and treating sepsis in the pediatric intensive care unit (PICU), but practices vary widely. Overuse can lead to false positive results and unnecessary antibiotics. Specific factors underlying decisions about blood culture use and overuse are unknown. Therefore, we aimed to identify perceived determinants of blood culture use in the PICU. Methods:We conducted semistructured interviews of clinicians (M.D., D.O., R.N., N.P., P.A.) from 6 PICUs who had participated in a quality improvement collaborative about blood culture practices. We developed interview questions by combining elements of the Consolidated Framework for Implementation Research and behavioral economics. We conducted telephone interviews, open-coded the transcripts, and used modified content analysis to determine key themes and mapped themes to elements of Consolidated Framework for Implementation Research and behavioral economics. Results:We reached thematic saturation in 24 interviews. Seven core themes emerged across 3 Consolidated Framework for Implementation Research domains: individual characteristics [personal belief in the importance of blood cultures, the perception that blood cultures are a low-risk test]; inner setting [adherence to site-specific usual practices, site-specific overall approach to PICU care (collaborative versus hierarchical), influence of non-PICU clinicians on blood culture decisions]; and outer setting [patient-specific risk factors, sepsis guidelines]. In addition, outcome bias, default bias, and loss aversion emerged as salient behavioral economics concepts. Conclusions:Determinants of blood culture use include individual clinician characteristics, inner setting, and outer setting, as well as default bias, outcome bias, and loss aversion. These determinants will now inform the development of candidate strategies to optimize culture practices.