Beyond the 9 to 5: A Cross-sectional Survey of Adult Antimicrobial Stewardship Programs in the United States on Their Initiatives and Resources Based on On-call Model Participation.

Background: Antimicrobial stewardship programs (ASPs) aim to optimize antimicrobial use through coordinated interventions that improve patient outcomes and reduce adverse events. While guidance exists from organizations including the Centers for Disease Control and Prevention and the Infectious Diseases Society of America, recommendations on effort allocation, working hours, and initiatives remain unclear. Methods: This cross-sectional survey assessed the institutional structure, effort allocation, initiatives, and on-call participation of adult ASPs in the United States from September to October 2024. The survey was distributed via email to several ASP-related listservs. Respondents indicating on-call participation were also inquired about working hours, initiatives performed, participants, and compensation. Results: Of 69 responses, most were from academic medical centers (59%) or community hospitals (35%), with 65% covering >500 beds. ASPs were often system-wide (78%) and primarily funded by their respective departments of pharmacy (87%). Common initiatives performed by all ASPs include answering ASP/infectious diseases questions, therapy de-escalation, and prospective audit and feedback. Twenty-four (69%) respondents indicated having an on-call model, with said programs reporting higher median inpatient full-time equivalents (FTEs) for physicians (0.5 vs 0.25) and pharmacists (2.9 vs 1.45) than those without. Commonly performed after-hours initiatives include preauthorization and answering microbiology inquiries. On-call coverage was generally performed during weekend daytimes and holidays, most often by pharmacists. Conclusions: This survey highlights differences in structure, effort allocation, and initiatives of ASPs based on on-call participation. Institutions participating in on-call reported higher FTE assignments for physicians and pharmacists and were more likely to perform time-sensitive initiatives.