1946. An Exploratory Study of the Therapeutic Reasoning Underlying Antimicrobial Selection

BACKGROUND: Clinical reasoning research has helped illuminate how clinicians make diagnoses but offers less insight into management decisions. The need to understand therapeutic choices is particularly salient within infectious diseases (ID), where antimicrobial prescribing has broad implications given increasing rates of resistance. Researchers have examined general factors underlying antibiotic prescribing. Our study advances this work by exploring the factors and processes underlying physician choice of specific antimicrobials. METHODS: We conducted individual interviews with a purposeful sample of Hospitalists and ID attendings. Our semi-structured interview explored the reasoning underlying antimicrobial choice through clinical vignettes. We identified steps and factors after 12 interviews then conducted 4 more to confirm and refine our findings. We generated a codebook through an iterative, inductive process and used Dedoose to code the interviews and facilitate analysis. RESULTS: We identified three antibiotic reasoning steps (Naming the Syndrome, Delineating Pathogens, Antimicrobial Selection) and four factors involved in the reasoning process (Host Features, Case Features, Provider and Healthcare System Factors, Treatment Principles) (Table 1). Participants considered host and case features when determining likely pathogens and antimicrobial options; the other two factors influenced only antimicrobial selection. From these data, we developed an antimicrobial reasoning framework (Figure 1). We also determined that participants seemed to have a “script” with specific content for each antimicrobial they considered, functioning much like the illness scripts common to diagnostic reasoning (Table 2). CONCLUSION: Our antimicrobial reasoning framework details the cognitive processes underlying antimicrobial choice. Our results build on general therapeutic reasoning frameworks while elaborating factors specific to ID. We also provide evidence of the existence of “therapy scripts” that mirror diagnostic reasoning’s “illness scripts.” Our framework has implications for medical education and antimicrobial stewardship. [Image: see text] [Image: see text] [Image: see text] DISCLOSURES: All Authors: No reported Disclosures.