BACKGROUND: The many etiologies of meningitis influence disease severity – most viral causes are self-limiting, while bacterial etiologies require antibiotics and hospitalization. Aided by laboratory findings, the physician judges whether to admit and empirically treat the patient (presuming a bacterial cause), or to treat supportively as if it were viral.OBJECTIVE: To determine factors that lead infectious disease specialists to admit and treat in cases of suspected meningitis.METHODS: A clinical vignette describing a typical case of viral meningitis in the emergency department was presented to clinicians. They were asked to indicate on a Likert scale the likelihood of administering empirical antibiotics and admitting the patient from the vignette and for eight subsequent scenarios (with varied case features). The process was repeated in the context of an inpatient following initial observation and/or treatment.RESULTS: Participants were unlikely to admit or to administer antibiotics in the baseline scenario, but a low Glasgow Coma Score or a high cerebrospinal fluid (CSF) white blood cell count with a high neutrophil percentage led to empirical treatment and admission. These factors were less influential after a negative bacterial CSF culture. These same clinical variables led to maintaining treatment and hospitalization of the inpatient.CONCLUSIONS: Most participants chose not to admit or treat the patient in the baseline vignette. Confusion and CSF white blood cell count (and neutrophil predominance) were the main influences in determining treatment and hospitalization. A large range of response scores was likely due to differing regional practices or to different levels of experience.