October 29, 2025
State-Level Malpractice Reforms Linked to Reduced Imaging for Headache in Emergency Departments
New Medicaid study reveals state tort reform is associated with less advanced imaging of headache patients.
A new Harvey L. Neiman Health Policy Institute study in the American Journal of Roentgenology (AJR) found that state-level malpractice reform measures are associated with 21% to 32% less use of advanced imaging for Medicaid patients presenting to emergency departments (EDs) with nontraumatic headache. The findings suggest that tort reform policies such as damage caps and several liability may reduce defensive medicine practices.
Researchers examined over 630,000 ED encounters for headache in 100% of adult Medicaid beneficiaries during 2019. They evaluated associations between imaging use during each ED visit and state-level measures of malpractice liability and tort reform policies. The primary focus, tort reform, included the presence of damage caps (i.e., a legal limit on the amount of money a plaintiff can recover from a defendant) and several liability (i.e., when a defendant is liable only for the share of damages they directly caused). The analysis revealed that both damage caps and several liability were independently associated with decreased advanced imaging utilization, both overall and for common imaging types used for headache, including CT, CT angiography (CTA), and MRI.
“Our findings reveal that tort reform in a state was associated with less use of advanced imaging for the common ED presentation of headache, highlighting how different medicolegal environments may impact defensive ordering of imaging, ,” said John Jordan, MD, MPP, FACR, Chair of the American College of Radiology Commission on Neuroradiology and study coauthor. “Understanding the impact of malpractice reform on imaging decisions is essential for informing policy that supports physicians’ appropriate clinical decisions and optimizes resource use.”
Overall, 39% of all headache-related ED encounters studied included advanced imaging. State-level presence of damage caps and several liability were significantly associated with 21% and 32% decreases in overall imaging utilization, respectively. For CT imaging alone, the corresponding decreases in use were 13% and 22%. Furthermore, state-level several liability was associated with 43% lower odds of undergoing CTA and 29% lower odds of MRI.
Among the malpractice measures evaluated, which may predict defensive ordering of diagnostic tests, several liability had the most significant effect on referral for imaging and was the only variable that was consistently significantly associated with imaging utilization both overall and across the three modalities examined.
“Our study shows how commonly a headache complaint in the ED results in imaging of Medicaid patients – 39% of all visits nationally. However, in states that have implemented tort reform measures, patients are 21-32% less likely to undergo imaging, even after controlling for other differences such as patient severity,” said Casey Pelzl, Principal Economics and Health Services Analyst at the Neiman Institute and lead author on the study. “These insights can be used to shape tort reform in states where legislation allowing for several liability or damage caps may not currently exist or is currently being argued.”
“This study adds to a growing body of evidence that state-level tort reform measures may reduce unnecessary imaging and promote more efficient use of healthcare resources,” said Elizabeth Rula, PhD, Executive Director of the Neiman Health Policy Institute. “Another interesting finding was that physicians in specialties other than emergency medicine were over eight-times more likely to order advanced imaging during an ED visit for headache compared with emergency medicine physicians. Our study did not explain why this discrepancy exists, but it should be the focus of future research.”
To arrange an interview with a spokesperson, contact Nichole Gonzalez at ngonzalez@neimanhpi.org.
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About the Harvey L. Neiman Health Policy Institute
The Harvey L. Neiman Health Policy Institute is one of the nation’s leading medical imaging socioeconomic research organizations. The Neiman Institute studies the role and value of radiology and radiologists in evolving health care delivery and payment systems and the impact of medical imaging on the cost, quality, safety and efficiency of health care. Visit us at www.neimanhpi.org and follow us on X, LinkedIn and Facebook.