Study objective: To characterize the association between emergency department (ED) clinician risk tolerance and the decision to admit, a common and high-cost decision.

Methods: In this observational cohort study, data on 100% of traditional Medicare beneficiaries for all ED visits in Massachusetts from October 2015 through September 2020 were linked to surveys of clinician risk tolerance. We estimated a generalized mixed-effect linear regression model to assess the association between the risk scales, divided into tertiles, and the decision to admit. The main outcome measure was ED disposition, defined as admitted or discharged to home. Risk tolerance was measured using 4 related scales: the Risk-Taking Scale, the Stress from Uncertainty Scale, the Fear of Malpractice Scale, and the Need for (Cognitive) Closure Scale.

Results: The total study sample included 421,301 ED visits seen by 889 emergency clinicians. Patients were predominantly women (57.4%), and the average age was 72.6 years. Mean clinician age was 46.5 years. In total, 77.1% were physicians, 59.3% were men, and 86.6% were White. We found a consistent relationship between lower risk tolerance and higher admission rates. This magnitude of the relationship was stronger for conditions with a higher rate of admissions.

Conclusion: The risk scales were significantly associated with the tendency to admit. This suggests that clinician risk tolerance meaningfully contributes to variation in clinician behavior and points to the potential utility for interventions that interface with clinician behavior to affect admission rates.