Defensive medicine and advanced imaging overuse in emergency departments: A focused review of imaging stewardship and overcrowding

Table 2 Emergency department imaging stewardship interventions graded by the strength of the supporting evidence, with the stakeholders involved, the point of workflow integration, suggested monitoring metrics, and potential unintended consequences

Intervention	Strength of evidence in emergency populations	Principal stakeholders	Workflow integration point	Suggested monitoring metrics	Potential unintended consequences	Ref.
Validated clinical decision rules	Strongest. Multiple prospective derivation and validation cohorts with defined eligibility criteria; implementation effect varies by site	Emergency physicians; nursing triage; radiology	At clinical assessment, before the order is placed	Rule documentation rate; rule-concordant imaging; missed clinically important injury; unscheduled return within 72 hours	Application outside the validated population; rule fatigue; documentation performed after the imaging decision	[61,62,65,68,69,75,82]
Computerized clinical decision support at order entry	Moderate to strong. Observational and implementation studies report improved appropriateness; effect depends on the guideline library and local configuration	Emergency physicians; radiology; informatics	Embedded in computerized order entry	Appropriateness score distribution; alert override rate; duplicate examinations avoided; time from order to acquisition	Alert fatigue; workflow interruption; systematic overriding; gaming of indication fields	[99,102,105]
Audit and feedback	Moderate but variable. Effects across sites are inconsistent and depend on timeliness and credibility of the data	Department leadership; quality improvement teams; individual clinicians	Periodic, outside the clinical encounter	Individual and peer ordering rates; diagnostic yield; guideline adherence; case mix adjustment	Perceived as punitive; distrust of unadjusted data; attention shifts to the measured test only	[22,48,58]
Choosing Wisely and awareness campaigns	Limited when used alone; greater when embedded in pathways and order sets	Professional societies; department leadership; patients	Local pathway and patient communication material	Uptake of targeted recommendations; rate of the specific low-value examinations named	Little effect without structural reinforcement; symbolic adoption without workflow change	[58,72,97,98]
Shared decision-making and decision aids	Limited and indirect in the emergency setting; most evidence is from non-emergency contexts or small studies	Emergency physicians; patients and families	During the clinical consultation	Documented discussion; patient-reported understanding and satisfaction; imaging rate in eligible presentations	Time cost in a crowded department; unequal uptake across language and health-literacy groups	[9,24,51]
Artificial intelligence-assisted appropriateness and triage tools	Emerging. Evidence of effect on imaging appropriateness is limited; where external validation has been performed, most algorithms lose performance on the external dataset	Radiology; informatics; emergency physicians; governance committee	Order entry, record extraction, or radiology worklist, depending on the tool	Local validation performance; drift monitoring; override rate; effect on report turnaround; equity of performance across subgroups	Automation bias; performance loss under dataset shift; opacity of the recommendation; unclear liability	[101,103,104,106,108,109]
Medico-legal reform and legal protection for guideline-concordant care	Weakest. Evaluated in few jurisdictions; the principal natural experiment found no accompanying reduction in advanced imaging	Legislators; hospital risk management; professional bodies	Outside the clinical pathway; institutional and legislative	Imaging rates before and after reform; malpractice claim frequency; clinician-reported medico-legal concern	Reform alone may not change behavior if institutional and consultant expectations are unchanged	[49,53,54]