What determines diagnostic resource consumption in emergency medicine: patients, physicians or context?

OBJECTIVES: A major cause for concern about increasing ED visits is that ED care is expensive. Recent research suggests that ED resource consumption is affected by patients’ health status, varies between physicians and is context dependent. The aim of this study is to determine the relative proportion of characteristics of the patient, the physician and the context that contribute to ED resource consumption. METHODS: Data on patients, physicians and the context were obtained in a prospective observational cohort study of patients hospitalised to an internal medicine ward through the ED of the University Hospital Bern, Switzerland, between August and December 2015. Diagnostic resource consumption in the ED was modelled through a multilevel mixed effects linear regression. RESULTS: In total, 473 eligible patients seen by one of 38 physicians were included in the study. Diagnostic resource consumption heavily depends on physicians’ ratings of case difficulty (p<0.001, z-standardised regression coefficient: 147.5, 95% CI 87.3 to 207.7) and—less surprising—on patients’ acuity (p<0.001, 126.0, 95% CI 65.5 to 186.6). Neither the physician per se, nor their experience, the patients’ chronic health status or the context seems to have a measurable impact (all p>0.05). CONCLUSIONS: Diagnostic resource consumption in the ED is heavily affected by physicians’ situational confidence. Whether we should aim at altering physician confidence ultimately depends on its calibration with accuracy.